① Many people have become walking advertisements. ② Even though we often say that we hate advertisements on television, radio, in magazines, and on signs, we don't seem to mind becoming advertisements ourselves. ③ Think, for example, how many of our cars have stickers on the back that advertise some amusement park or tourist attraction we have visited. ④ And what about our clothes? ⑤ We proudly show off the names of designers on our sports shoes, our shirts, and our jeans. ⑥ And we wear T-shirts covered in all kinds of advertising messages. ⑦ For instance, people are happy to wear shirts that read "Coca Cola," "Nike," and "I Love NY." ⑧ So tell me, do you really hate advertisements?

① Every culture contains an unspoken "schedule" that tells people when to take important steps in their life, such as when to begin dating, when to buy a home, and when to start a family. ② This timetable functions as a kind of social clock, letting you know whether you're getting ahead of your peers, keeping pace with them, or falling behind. ③ Using this clock, you are able to evaluate both your social and professional development. ④ If you find that you are keeping up with your peers, you are likely to feel comfortable, well adjusted, and socially accepted. ⑤ However, if you find yourself running late, you're more likely to experience anxiety and dissatisfaction. ⑥ Though the social clocks of many modern cultures have grown more flexible and less intolerant of deviations from the expected schedule, they still push people to keep up with their peers.

① When eating out, people trying to save money might skip dessert or share a dish with a friend. ② However, research suggests that this is not the best way to spend less in a restaurant. ③ A better idea is to order your meal before the people you are eating with. ④ A study showed that peer pressure has a strong effect on what you choose to eat. ⑤ If your friends order expensive meals, you probably will too—even if you can't afford to. ⑥ But by ordering first, you can make an affordable choice without any peer pressure. ⑦ Even if your friends order something expensive after you, your mind has already been made up. ⑧ It is also a good idea to check the online menu first and choose your dish before you go out. ⑨ Then stick with it when it's time to order. ⑩ This will help you make an affordable choice and lower your spending.

① Good news is no news, but bad news sells. ② This is the general rule that most news organizations—newspapers and television news programs—have followed. ③ Nowadays, however, most news stories are available online, and people post them on social media to share them with friends and family. ④ In this case, researchers have found that good news spreads farther than bad news. ⑤ In other words, people are more likely to email a news story to a friend or post it on their social media page if it has a positive message. ⑥ This difference may be due to the fact that news organizations only care about the number of viewers or readers they get. ⑦ They don't care about how viewers feel after they've seen, heard, or read the story. ⑧ But when people share stories, they do care about how their friends react. ⑨ And most of them would rather put their friends in a good mood than make them feel sad.

① Plagiarism is risky behavior that students engage in as a result of a variety of motivations. ② There are some, for example, who are too lazy to conduct the research and put together the words needed to produce an original essay. ③ Of course, in most cases, there is more than just laziness behind the attempt to plagiarize. ④ Students today may feel that they must outperform their peers to succeed. ⑤ Thus they may be more focused on the end results of their research rather than the skills they pick up by performing it. ⑥ Sadly, another reason why students copy work from others is they believe that other students are doing the same and that they must plagiarize so as to keep up.

① Many people suffer from a fear of speaking in front of an audience. ② However, from our earliest years of childhood, we develop into able storytellers. ③ Just by observing everyday conversations at school or in the workplace, we can see that storytelling is an integral part of socializing for everyone. ④ We all do it, all the time, to the point that we don't even notice. ⑤ However, as soon as we realize that we have to tell a story in front of a crowd, our fear of public speaking kicks in. ⑥ Even if we have an interesting narrative, many of us have difficulty delivering it with confidence. ⑦ Adapting to storytelling on a stage is not like learning a new skill. ⑧ It simply requires the use of our instinctual, unconscious abilities, but in a high-pressure environment instead of a casual one. ⑨ We just need to figure out how to make that switch.

① Being kind toward others is always the right thing to do. ② However, kindness might have even more benefits than most people realize. ③ Studies have shown that acts of kindness strengthen the immune system. ④ They also cause the brain to produce more serotonin, a natural substance that makes us feel more relaxed and peaceful. ⑤ In fact, medicine used to fight depression works in the same way—. ⑥ It increases the body's serotonin production. ⑦ These positive effects take place in both the person who receives the act of kindness and the person who performs it. ⑧ Surprisingly, even a person who simply sees an act of kindness can experience the same kind of effects. ⑨ This new information gives people another good reason to treat each other kindly.

① In an effort to make its subways and buses less crowded at rush hour, Singapore's Ministry of Transport started offering free rides to early-morning passengers. ② As a result, 7 percent of commuters changed their habits to take advantage of the offer. ③ Since the new policy was established, Singapore's transit system has become much more comfortable for morning commuters. ④ And a smoother ride for passengers is not the only benefit of this move. ⑤ Indeed, people who did not normally take public transportation in the morning started opting to do so instead of driving to take advantage of the free rides. ⑥ Thus, a secondary effect of the free early-morning commute has been a reduction in congestion on the roads, which means that drivers also benefit from the decision. ⑦ In the future, other cities suffering from rush-hour problems might decide to follow Singapore's example.

① According to recent studies, when given praise, children are likely to continue an activity as long as an adult is watching;. ② However, these children are less likely to continue the activity once the adult leaves. ③ What's more, they may not participate in the activity in the future. ④ It seems that praise, rather than encouraging children to adopt positive behavioral traits, motivates them to seek out ways to get further verbal "treats" from important adults. ⑤ In a way, praise is like a thick layer of icing on a cake. ⑥ It looks appealing, and its sweet taste is wonderful at first. ⑦ After a few more bites, however, this sweetness seems excessive. ⑧ In fact, if we eat too much of this one simple flavor, we may start to feel illness. ⑨ Like praise, it provides a quick burst of energy but offers no nourishment and doesn't support healthy growth.

① In our efforts to be the good child, the uncomplaining employee, or the cooperative patient, many of us fall into the trap of trying to please people by going along with whatever they want us to do. ② At times, we lose track of our own boundaries and needs, and the cost of this could be our life both symbolically and literally. ③ When we are unable to set healthy limits, it causes distress in our relationships. ④ But when we learn to say no to what we don't feel like doing in order to say yes to our true self, we feel empowered, and our relationships with others improve. ⑤ So don't be afraid to say no. ⑥ Try to catch yourself in the moment and use your true voice to say what you really want to say.

① Educating children about not being rude is an important part of their upbringing. ② But this type of teaching often focuses on influencing the children's behavior rather than changing what is in their hearts. ③ Parents usually teach them on how their bad behavior will affect them. ④ "If you run in the hall," we tell them, "you will hurt yourself." ⑤ However, this is not the proper way to teach good manners to our children. ⑥ It doesn't help them understand how others are personally affected by their behavior, so it won't make them become better people. ⑦ Instead of focusing on what might happen to children if they run in the hall, we should tell them how it makes others feel. ⑧ This gives them another reason to improve their behavior. ⑨ Unless we teach children the responsibilities of living in a society, we aren't truly educating them.

① Since 1990, more than 250 people have been killed in stock car racing accidents, including 29 spectators, five of whom were children. ② Take into consideration the countless injuries that have occurred, as well as the psychological damage they may have caused. ③ There is no denying that the sport of automobile racing is dangerous, but the racing industry has no excuse for not providing better protection for its spectators. ④ The positioning of fans should be considered carefully and adequate fencing erected to keep them safe from harm. ⑤ Furthermore, emergency crews should be kept on hand and drivers educated in safe driving techniques. ⑥ With improved safety measures, stock car racing can expect an increase in its popularity.

① Heat waves, floods, and droughts are becoming more and more commonplace. ② As most experts agree, this is due to climate change caused by carbon emissions, so now is the time for businesses to start investing in low-carbon alternatives. ③ However, there are considerable objections to this idea. ④ Many people assert that because this would be too costly, we should continue operating in traditional ways. ⑤ They argue that continuing business as usual is the cheaper option. ⑥ However, the US agricultural industry was recently hit hard by a drought, which caused billions of dollars in losses. ⑦ If we don't take action, this will happen again and the cost will be even more devastating. ⑧ By investing in energy-efficient technology, we can prevent this kind of disaster while also creating new jobs, stabilizing the economy and protecting the planet.

① I believe that we each have a natural fountain of ideas in our mind, which we can use to create. ② I like to call it "the idea spring." ③ This spring of creativity brings ideas deep in our minds up to the surface, and we all need to feed the spring and care for its environment. ④ If we don't, it may dry up or become toxic. ⑤ I suggest that we make time once a week to do something in order to ensure that the spring remains active and we stay full of ideas. ⑥ You can visit an art gallery or find a quiet place in nature to meditate. ⑦ It is important for you to do it by yourself, to avoid the complexity of your social life and simply take in the joy of the activity. ⑧ This is your weekly "art outing," when you spend part of the day enjoying new ideas.

① Although many people believe otherwise, most developing countries performed better before free-market policies were introduced. ② Previously, development efforts were led by the government. ③ This sometimes ended in failure, but overall growth was faster in those days. ④ Despite this, developed countries continue to urge developing countries to adopt free-market policies. ⑤ Another incorrect belief is that the developed countries became rich because of these free-market policies. ⑥ In fact, almost every rich country in the modern world obtained its wealth by protecting its industries from foreign competition and providing these industries with financial aid. ⑦ These are the exact policies that developing countries are now being advised to avoid. ⑧ Meanwhile, the policies they are being encouraged to pursue are unlikely to make them wealthy.

① From a political perspective, hostage situations are horrifying events, primarily because they paralyze governments and make them powerless to act. ② Knowing that captives' lives lie in the balance, politicians may be tempted to negotiate with hostage takers. ③ It might seem like the only possible option, but this must be avoided at all costs. ④ By making concessions to terrorists, politicians set a precedent for the future that suggests to other terrorists that the taking of hostages may enable them to succeed in their goals. ⑤ Paying ransom to hostage takers practically ensures that this fund-raising method will be attempted again. ⑥ It is essential that governments take a firm stance on this issue to demonstrate that under no circumstances does hostage taking work.

① Dear Coach Johnson, My name is Christina Markle, and I'm Bradley Markle's mother. ② Bradley and I were thrilled to learn that you're holding your Gymnastics Summer Camp again this year. ③ So I didn't hesitate to sign up and pay the nonrefundable deposit for the second week program, which is from July 13 to 17. ④ But today I remembered that our family is going to get back from a trip on July 13, and I'm afraid Bradley won't be able to make it on the very first day of the program. ⑤ Rather than make him skip the day, I'd like to check to see if he could switch to the third week program. ⑥ Please let us know if that's possible. ⑦ Thank you. ⑧ Sincerely, Christina Markle

① I have enjoyed KVE cameras for many years. ② Unfortunately, after purchasing your latest model, the Photoking 3000, I was extremely disappointed. ③ I purchased it earlier this year, on January 6th, and it no longer functions properly. ④ Specifically, the camera lens does not focus well, resulting in blurry photos. ⑤ I brought it to my local service center for repairs, but the service was terrible, and the problem was not fixed. ⑥ Now I am frustrated with both the poor quality of your repair service and the camera. ⑦ I'm afraid I must demand a full refund. ⑧ I have enclosed copies of my purchase receipt and the repair bill.

① Nursery school provides children below school age with a place to learn and play. ② Young children who attend nursery school receive important educational training that effectively prepares them for success later in life. ③ However, as this type of education is not generally provided for free, it is only children from wealthy families that tend to benefit from it. ④ This means that those children whose parents can't afford nursery school fees will be disadvantaged from the start. ⑤ Over time, this will only serve to deepen social and economic inequalities. ⑥ Accordingly, providing free public nursery school for all would be a powerful first step in ensuring that all children have an equal chance at academic achievement. ⑦ Not only would this benefit individual learners, but it would also help build a stronger, fairer society.

① Starting next semester, the campus bookstore will be instituting a policy change that will have a direct effect on students. ② The ultimate goal of this change is to ensure that used books are available to students who need them, and are not being purchased by students who will soon return them. ③ We are facing a problem where students purchase used books for all the classes they might take, and then return the unneeded ones once their schedule is fixed. ④ This unfairly causes other students to purchase expensive new books when used ones should have been available. ⑤ This new return policy, therefore, is designed to ensure that students do not purchase any books before their schedule is fixed.

① At Leena Inc., we've been creating innovative clothing designs for ten years. ② In our quest to continue to progress and produce even more creative designs, we recently joined forces with Sapto, a company which specializes in accessories. ③ While Sapto used to be our competitor, it is now a strong partner. ④ More than just an investment, this move is helping us rebrand our style and products. ⑤ To continue this wave of changes, we have decided to abandon the name "Leena," which we feel no longer accurately represents our image. ⑥ Thus, we will now be known as "Frolics." ⑦ We believe this name reflects the style that we aim to create through our new collaboration. ⑧ We look forward to serving our customers with even more imaginative and fun designs, and we trust that they will find themselves easily connecting with our reconceptualized brand.

① As always, thank you for taking an active part in your children's education by reading this newsletter. ② This month, all grade levels will attend a special safety course. ③ The local police department has received several calls about strangers trying to kidnap children. ④ Parents said that a stranger tried to give their children candy or asked the children to get into a car. ⑤ To make sure your children are safe, we're planning a new program to protect children from any dangerous incidents that might happen. ⑥ Each Friday, we're going to invite teachers and police officers to teach students how to stay away from strangers. ⑦ The students will also practice important skills, especially how to get away from dangerous situations. ⑧ We will send you more information soon. ⑨ Thank you for reading, and have a pleasant month.

① We are aware of the strong reputation Greenfresh Supermarkets has as a responsible business. ② As your customers, we strongly support your environmental campaigns every year and your efforts to help our poor neighborhood. ③ As your company is concerned about social issues, you've undoubtedly already recognized that our society is alarmingly overweight. ④ Despite this, we recently noticed that there are no alternatives to the pizza, burgers, and other high-fat meals served in your food courts. ⑤ We therefore suggest that you offer some additional items. ⑥ Vegetarian burgers and veggie wraps are good choices to think about. ⑦ Both can be made completely cholesterol free, with little or no sodium. ⑧ They would most likely be popular with shoppers and help increase your food court sales. ⑨ You may even be able to promote Greenfresh's new menu items as part of a weight-loss campaign. ⑩ We hope you consider our suggestion.

① Key fobs allow you the convenience of unlocking your car from a distance, so they're widely used today. ② However, they are a major security risk. ③ Hackers can use a special device in order to find your key fob signal and relay it to your car. ④ This means they can unlock your car even if your keys are lying on the kitchen counter. ⑤ It's hard to believe, but criminals are already doing this. ⑥ Luckily, you can prevent this in a couple of ways. ⑦ You can buy special key fob holders that block the signal your key fob emits. ⑧ Or, to save money, simply put your key fob in the microwave or refrigerator. ⑨ These appliances have thick metal walls, which can contain your key fob's signal. ⑩ Before doing this, however, read the product information for your key fob to make sure it won't cause any harm.

① Even a century after her death, Florence Nightingale's memory lives on because of the important role she played caring for the wounded during the Crimean War. ② Of course, Nightingale did not die immediately after returning home to England from the war and in fact lived on for more than 50 years. ③ During the post-war decades, Nightingale conducted medical research that led to major improvements in military and civilian care. ④ She distributed information about sanitary techniques to hospitals, promoted training for caregivers, and set up nursing schools. ⑤ It might not be an exaggeration to suggest that the profession of nursing would not have been established without Nightingale's dedication to her line of work.

① I'd been afraid of spiders my whole life. ② But when I noticed that my fear was taking over my life, I knew it was time for a change. ③ To get over it, I decided to buy a tarantula. ④ I remember the day the package arrived like it was yesterday. ⑤ Knowing that I would soon see a monster with numerous hairy legs was terrifying. ⑥ When the box was open, I could not stop yelling every time the spider moved! ⑦ However, it's been six years since then, and now I have 58 tarantulas living in cages arranged on my living room shelves. ⑧ They're very easy to look after, and I even find them cute. ⑨ If you face your fear and overcome it, it's possible to fall in love with what you were once scared of.

① When we talk about the Internet, the word "cookie" is given a new meaning. ② It refers to the small files left behind on your computer by the websites you visit. ③ Within these cookies, personal information, such as your email address, is stored for when you return to the website at a later time. ④ Cookies can be used to give you content that may interest you or to automatically log you in upon your arrival. ⑤ While in some ways helpful, cookies can also decrease the security of your computer. ⑥ Keep in mind that your browser gives you the option to choose whether or not to accept cookies, allowing you some measure of control over them.

① Oil spills are obviously a danger to creatures that live in the sea, but they can also be harmful to aquatic birds. ② These birds depend on the sea as a source of food and often live on the coast. ③ While some migrate with the seasons, others build their nests in one place. ④ Aquatic birds that live in large groups, spend a lot of time on the water, and reproduce at a relatively low rate are the most likely to be negatively affected by oil spills. ⑤ What's more, some aquatic birds don't fly when they are molting, and others—such as penguins—don't fly at all. ⑥ These species face the greatest risk, as they are more likely to come in contact with spilled oil. ⑦ This can happen when they are floating on the ocean's surface or diving to catch fish.

① Nowadays, the name of British physician Peter Mark Roget is remembered for an accomplishment that was unrelated to his career in medicine. ② Roget believed that a dictionary organized not in alphabetical order but according to the meanings of words might be a useful tool in some situations. ③ His first edition of this modified dictionary was published in 1852, and it featured 15,000 words. ④ Each edition that followed included more entries, and Roget never stopped adding words to the collection. ⑤ These days, Roget's Thesaurus is used by millions of people all over the world who write in, study, or speak the English language. ⑥ It is continually being updated, and new editions of the book appear frequently.

① "I shop, therefore I am." ② This witty paraphrase of René Descartes' famous philosophical statement, "I think, therefore I am," sums up the essence of modern people's consumption behavior. ③ Once upon a time, people shopped only when they needed something. ④ Now people visit the mall as an important part of life, as entertainment. ⑤ Today, the mall is like the town square of the past, where people of the village would gather to pass the time. ⑥ Even if you don't need anything, even if you aren't going to shop today—come to the mall.

① Apologies often fail. ② One reason apologies fail is that the "offender" and the "victim" usually see the event differently. ③ By examining personal narratives, researchers have found that those who cause harm tend to minimize the offense—probably to protect themselves from shame and guilt. ④ They also tend to downplay the consequences of their actions. ⑤ However, these tendencies can worsen the anger of the hurt person. ⑥ Most likely, the person who was harmed will think the incident was worse than it was, and might see the offender's attitude as unfair or even immoral. ⑦ Both people have their own perspectives, and neither side is totally true. ⑧ Therefore, to apologize sincerely we must first listen attentively to how the other person really feels about what happened—not simply assert what we think happened.

① Have you ever noticed that the buttons on men's clothing and women's clothing are arranged differently? ② On men's shirts, the buttons are located on the wearer's right-hand side. ③ On women's shirts, they are on the left-hand side. ④ This is because of a tradition that began when clothing with buttons was expensive. ⑤ Women who were wealthy enough to buy button-up clothing rarely dressed themselves. ⑥ Instead, they were dressed by maids, who, like most people, were usually right-handed. ⑦ Therefore, clothing makers made it easier for the maids to fasten the buttons by putting them on the wearer's left-hand side. ⑧ Today most people dress themselves, but clothing makers are reluctant to change such a well-known tradition.

① The Inuit art of carving has the ability to transcend both time and language and speak to the observer directly. ② Some carvings are thousands of years old, yet they continue to be admired today. ③ Each time we view a carving masterpiece, we discover a new layer of meaning we hadn't seen before. ④ Perhaps the outline of an animal suddenly makes itself obvious, or an image suggesting a mystical world takes shape. ⑤ Though created in arctic surroundings, these works of art can't be described as cold. ⑥ Rather, they display the movement and excitement of the Inuit culture—their passion for life and respect for the world around them.

① To collect information about lies, a university professor conducted an experiment. ② She had 150 participants keep a daily journal in which they listed all the lies they told. ③ Additionally, she asked them to note how they felt during and after the telling of the lie. ④ At the end of the study, all of the participants admitted they had lied at least once a day. ⑤ Moreover, the lies they recorded occurred in all types of social situations, from quick chats with strangers to long talks with loved ones. ⑥ Most of the liars expressed no guilt, saying if given the chance, they would tell the lies again.

① One common misunderstanding that the public has about penguins is about their habitats. ② Many people think that penguins only live in the brutally cold climates of the South Pole. ③ However, of the seventeen species of penguins, only four are capable of living in Antarctica year round. ④ Adelie, chinstrap, gentoo, and emperor penguins have all evolved special characteristics that allow them to live in the harsh environment. ⑤ These include a thermoregulation system and survival instincts that make living both on the ice and in the frigid water possible. ⑥ Other species of penguins spend part of their time in Antarctica, but migrate to warmer areas during breeding season.

① Some people believe that vaccines cause autism. ② Although it's easy to ignore such factually incorrect beliefs, we should take a closer look at how people come to this kind of conclusion. ③ Actually, we all have certain human characteristics that can lead to the denial of scientific facts. ④ Conditions that don't have an obvious cause, such as autism, make us uncomfortable, so we tend to fill the gaps in our knowledge with unproven connections. ⑤ What's more, when facing something that seems to be a risk, we often come up with the worst possible scenarios in our minds rather than approaching the situation rationally. ⑥ This is what happens with vaccines—people who don't understand them find it is easy to imagine they're harmful, despite the data that shows this is untrue.

① Regardless of where you are, you have a much better chance of avoiding injury during an earthquake if you keep this response in mind: drop, cover, and hold on. ② These three steps stand for dropping to the floor, taking cover under a sturdy object, and holding onto it tightly. ③ If possible, you should also change your location to stay away from danger zones, such as immediately next to a building's exterior wall. ④ There, you're exposed to falling windows and architectural ornaments, which are quick to collapse during a quake. ⑤ To protect yourself from this danger zone, remember to avoid leaving or entering buildings while the earthquake is in progress.

① The reality of life on our planet is that productive resources are limited, while the human desire for goods and services is virtually unlimited. ② Would you like to have some new clothes, a luxury boat, or a vacation in the Swiss Alps? ③ You may dream of driving a brand-new car into the driveway of your oceanfront house. ④ Most of us would like to have all of these things and many others. ⑤ However, we are constrained by the scarcity of resources, including a limited availability of time. ⑥ Because we cannot have as much of everything as we would like, we are forced to choose among alternatives. ⑦ There is no free lunch: doing one thing makes us sacrifice other opportunities.

① When researchers find that two variables are related, they often automatically leap to the conclusion that those two variables have a cause-and-effect relationship. ② For example, suppose a researcher found that people who took vitamin C every day reported having fewer colds than people who didn't. ③ Upon finding these results, she wrote a paper saying vitamin C prevents colds, using this data as evidence. ④ Now, while it may be true that vitamin C does prevent colds, this researcher's study can't claim that. ⑤ That's because she didn't control for any other factors that could be related to both vitamin C and colds. ⑥ For example, people who take vitamin C every day may be more health-conscious overall, washing their hands more often and exercising more. ⑦ Until you do a controlled experiment, you can't make a cause-and-effect conclusion based on relationships you find.

① Before they were swimming around in fishbowls, goldfish were actually served for dinner in many Chinese households. ② The goldfish we know now are a cultivated version of a wild carp that is silver-gray in color. ③ Known as chi, the wild carp used to be the most frequently eaten fish in China. ④ In the wild, they would sometimes appear with vivid red, yellow, or orange scales because of genetic differences. ⑤ Since such colors were easily seen, these fish would be quickly attacked and eaten by predators. ⑥ However, starting around the ninth century, Buddhist monks started keeping brightly colored chi in ponds. ⑦ This kept the fish safe from natural predators. ⑧ Soon after, more and more people across China started keeping chi as pets instead of preparing them for dinner.

① All living things suffer during water shortages. ② Yet some animals, particularly those in places with dry seasons, have amazing adaptations that help them survive dry conditions. ③ Two such animals, the Galápagos tortoise and the desert tortoise, save up water in their bladders. ④ Drinking water from rainfall and green plants allows them to fill their bladders. ⑤ The tortoises can then survive on the stored water throughout the dry period. ⑥ Other dry-climate animals have adaptations that allow them to keep water in. ⑦ For example, a special kind of toad in North America called the desert spadefoot spends 75 percent of its time deep under the ground. ⑧ There, it wraps itself with a sticky temporary skin that keeps water from escaping. ⑨ In the seasonal rains more than nine months later, the spadefoot comes out again.

① Most of us take zippers on our clothing for granted today, but when this technology was first invented, some people found it unappealing. ② The first patent for a zipper, awarded in 1893, went to a Chicago engineer. ③ At that time, his device didn't work very smoothly. ④ Although an improved version was introduced in 1913, the public was still hesitant to adopt it. ⑤ This was because it wasn't the quality of the device that people disapproved of. ⑥ In fact, the problem wasn't a mechanical issue at all; rather, the problem was a moral one. ⑦ Providing added convenience in putting on and taking off clothing, the zipper was seen as indecent by people who questioned the desire to get in and out of clothes so fast. ⑧ For this reason, use of the zipper was slow to spread.

① According to the environmental journal Green Chemistry, scientists at Queen's University Belfast have developed a more eco-friendly way of breaking down wood to get the different elements. ② The current method, which was developed in the 19th century, involves the use of dangerous chemicals that pollute the environment. ③ Nevertheless, there have been no suitable alternatives until now. ④ Even if some potential replacement processes have been suggested, they are equally damaging to the environment. ⑤ The new process, however, doesn't require any polluting chemicals. ⑥ Instead, it uses an ionic liquid, along with moderate pressure and temperatures, to break down chips of both softwood and hardwood. ⑦ Then water and a water-acetone mixture are added, which separates the wood's key components, lignin and cellulose. ⑧ Experts welcome the discovery, hoping it will help make the chemical industry more sustainable and environmentally friendly.

① The slavery of today looks different from that of the past. ② There are no physical chains keeping present-day slaves from leaving their workplaces. ③ However, these laborers have no other choice but to continue working in sweatshops in order to avoid punishment or a life of poverty. ④ They toil away in harsh conditions to make the things we buy, and they endure abuse daily while earning only a few pennies an hour. ⑤ Those who want to stop labor exploitation have good intentions but are not addressing the problem in a way that will make a real difference. ⑥ If they truly want to end modern slavery, they must tackle the global economic system that cares more about profits than the protection of resources and welfare of workers. ⑦ Developed countries and the global consumer should acknowledge the role they play in what happens in these sweatshops. ⑧ To stop modern slavery, they'll need to pay the true cost of products.

① People first began to realize that humans have a biological need for touch during the 19th century. ② In the U.S., thousands of infants who were sent to orphanages began to mysteriously die at this time. ③ Although they were fed and taken care of, they kept losing weight until they passed away. ④ As recently as 1920, nearly all the infants under the age of one who were sent to orphanages died from this condition. ⑤ Researchers assumed that the cause was a lack of physical contact. ⑥ Infants raised at home spent much of their time in their parents' arms, but those raised in orphanages did not. ⑦ Using this assumption, orphanage staff members began to make sure to pick each baby up and carry it around several times a day. ⑧ As a result, the infant death rates in these institutions immediately dropped.

① The Greek historian Herodotus wrote a story about cinnamon, which he had learned of from the Phoenicians. ② The Phoenicians had claimed that cinnamon sticks were brought to Arabia by large birds that carried them to their nests on mountain cliffs. ③ In order to get the cinnamon, Arabians cut up the bodies of large animals and placed them on the ground near the nests. ④ When the birds picked up the food and returned to their nest, the weight of the meat broke the nest and the cinnamon fell down the mountain, where the Arabians ran to pick it up. ⑤ The spice was then exported to other countries. ⑥ This story is perhaps unlikely. ⑦ For those who traded this spice to people from far-off lands, however, such an exaggerated tale of hardship may have increased a product's value to the consumer.

① For over a year, I have been saving all my allowance—three dollars a week. ② In addition, I have been earning more money doing jobs such as washing my aunt's car and weeding our neighbor's garden. ③ In just a few more weeks, I'll have enough money for that terrific 24-speed bike I want. ④ But some of my friends think I'm silly to work and save for a bike. ⑤ They spend their money on electronic gadgets or buy all kinds of new clothes so that each of them can impress the others. ⑥ I like those things, too. ⑦ But the bike is so much more important to me that I don't mind doing without electronic gadgets and extra shirts.

① Some flower species, such as Rafflesia flowers and Arum maculatum, produce odors similar to those of rotten meat or fish. ② The reason for the plants' stink has to do with reproduction. ③ As plants, they can't move around in order to find a mate and reproduce. ④ Instead, the odor the flowers give off attracts flies, which land on the flowers and become trapped by thick hairs. ⑤ Soon, the hairs fall out and the flies are free to move on. ⑥ When they leave, they take a bit of flower pollen with them. ⑦ Later they will land on a flower of the opposite sex, drop the pollen, and enable the reproductive process to begin.

① Nowadays, a lot of countries are evolving into cashless societies. ② In Sweden, cash circulation of currency dropped dramatically, and it now accounts for only 2% of the nation's transactions. ③ This evolution has had several positive effects. ④ Financial institutions have been able to make bigger profits thanks to the reduction in cash-handling services. ⑤ Moreover, bank robberies across the country have almost disappeared. ⑥ Nevertheless, a cashless society does not benefit everyone. ⑦ While the elderly struggle with the technology, the younger generations are more prone to overspending when no physical money is exchanged. ⑧ Furthermore, this progression raises several ethical concerns, such as threats to individual privacy. ⑨ Therefore, before the day of 0% cash circulation comes, several legal and political issues need to be resolved.

① Young children, unlike adults, react to sounds with their emotions instead of their intellect. ② For example, consider how a child would react if you yelled these words directly at him or her: "I can't stand you being naughty, and I want you out of my sight!" ③ What would happen? ④ Obviously, the child would respond with alarm or fright and probably begin to cry. ⑤ The interesting thing, though, is what happens when you use the same shouting voice to say: "I love you very much and I want to spend time with you!" ⑥ To these words, the child would respond in exactly the same fashion. ⑦ This is because the raw sound of your voice triggers the reaction before the child has a chance to interpret your words.

① During colonial times, mapmakers demonstrated extraordinary ignorance regarding the features of Africa, and this led to some rather incredible mapping errors. ② For instance, in the late 1700s, a European explorer brought back a report of several mountains in Guinea, West Africa. ③ Accepting it as fact, a mapmaker drew a map of Africa with a large chain of mountains, calling them the "Kong Mountains." ④ This map was copied again and again, and the mountains remained. ⑤ Important decisions were made by politicians and businesspeople based on the blind assumption that these mountains existed. ⑥ The misconception lasted over 100 years, until another explorer was finally able to show that there were no such mountains in Guinea. ⑦ Only then were maps corrected, and the mysterious mountain range was erased.

① In the middle of war, when life seems too difficult to continue, refugees rather accept the danger of a risky journey, such as boarding a boat that may sink. ② Although their journey is hard to endure, losing their homeland is more painful to the refugees. ③ The damage done to the body is easily seen, but the damage to the mind is even more severe. ④ No longer a member of a society, with a name, an address, relatives, and a wide circle of friends, they have become "exiles." ⑤ They fear they are losing themselves. ⑥ Therefore, in an attempt to preserve their sense of identity, refugees cling to memories from "the old country." ⑦ Some, for example, carry clothes with them that are no longer practical, such as uniforms from their old jobs. ⑧ From time to time they try them on, as if to remind themselves of who they were.

① With societies so focused on individual freedoms these days, it is important to remind ourselves about the true reason we have social laws. ② Although these laws limit our personal freedom to some degree, they do so to protect our overall freedom. ③ When a policeman pulls you over for speeding, for example, you may feel like he restricts your freedom. ④ But he is actually a symbol of liberty rather than one of tyranny. ⑤ Think what would happen if everyone were allowed to drive as fast as they wanted. ⑥ The roads would be extremely dangerous, and you would be too afraid to even leave your house. ⑦ Likewise, laws and rules seem to curtail our freedom, but they ultimately allow us to enjoy it.

① If you are an average person, you will take about 150 million steps during your life. ② That's a lot of steps! ③ Surprisingly, all of those footsteps might someday help end the world's energy problems. ④ A company has invented floor tiles that create electricity when a person steps on them. ⑤ The combination of the weight of the person and the slight movement of the tile is used to create an electrical current. ⑥ When stepped on, the rubber tiles move downward just about five millimeters. ⑦ That's not much, but it's enough to create kinetic energy, which is stored in a battery. ⑧ These tiles are currently being used in London, where they can be found in a subway station and on the sidewalk in front of a shopping mall.

① The Formula 3 racing car that Warwick University researchers unveiled is unlike typical vehicles. ② Not only is it built from materials derived from vegetables, it also runs on chocolate! ③ The car's body is made of components that come from plant sources such as carrots, potatoes, and soybeans, and it uses a special biodiesel engine that is powered by fuel made from waste chocolate and vegetable oil. ④ The researchers used these materials in the way carbon fiber, plastics and oil are used in traditional racing cars. ⑤ But don't let that fool you into believing it's not a car designed to race. ⑥ Despite the car's environmentally-friendly design, it is able to reach speeds of around 145 mph. ⑦ The Warwick team is dedicated to proving that just because something is green doesn't necessarily mean it is boring.

① The fair trade movement works to promote fair labor standards around the world. ② It began in Europe in the 1960s with shops selling handicrafts produced by the poor. ③ The first fair trade label was introduced in 1988 in the Netherlands, and was designed to help coffee growers. ④ It eventually evolved into the current fair trade mark, a symbol that is easily recognized across the globe. ⑤ Thousands of farmers and goods producers have been involved with the movement, which has improved their working conditions and transformed their lives. ⑥ Thanks to fair trade, they have been empowered to negotiate with their employers on equal terms.

① Although leading a simple life is possible, it is not enough for humans. ② The reason can be easily understood when you ask yourself what humans are, what we need, and how we go about getting it. ③ Simply living life in its most basic form is not adequate. ④ We actually require much more if we wish to prosper and thrive. ⑤ We need things like companionship, comfort, love, security and leisure. ⑥ Without purposeful work, creative pursuits, and people to share our experiences with, there is little to motivate us. ⑦ As a species, we are always striving for more than just the necessities of life, searching for ways to expand not only the structure of our own lives but that of our entire culture as well. ⑧ For us, perhaps unlike other species, happiness lies in growth, change, and improvement.

① Do you know why some people think that they see ghosts? ② Surprisingly, the answer might be related to infrasound, sounds that lie below 20 Hz. ③ These sounds can have a physical effect on our body. ④ One researcher showed that a certain infrasound frequency has an interesting effect on our eyes. ⑤ It began when he saw a mysterious gray blob out of the corner of his eye while working late one night. ⑥ Trying to determine its cause, he eventually realized that a fan in his room was emitting a frequency of 18.98 Hz. ⑦ This is very similar to the resonant frequency of the human eye. ⑧ Therefore, he concluded that the gray blob was actually caused by resonation in his eyes. ⑨ Based on his research, he created a theory that "ghosts" are just optical illusions caused by infrasound.

① We often hear of rich and successful people with great jobs and large homes who simply aren't happy. ② However, you'll never hear anyone say this about a dog. ③ Dogs are happier than people because they aren't affected by outside circumstances as much as we are. ④ For example, when I take my dogs out for a walk on a cold and rainy day, they're just as excited as they would be on a sunny day. ⑤ The minute I open the front door and call their names, they come running excitedly, ready for a new adventure. ⑥ I put on my raincoat, and we all run outside together. ⑦ The fact that it is pouring and the ground is muddy beneath their feet means nothing to the dogs. ⑧ As I carefully make my way around large puddles, my dogs run happily through them. ⑨ And it doesn't seem to bother them one bit.

① What distinguishes recycling is not its importance, but rather the ease with which individuals can participate, and the visibility of actions taken to promote the common good. ② You may care passionately about the threat of global warming or the destruction of the rain forests—. ③ But you can't have an immediate effect on these problems that is perceptible to yourself or others. ④ The rain forest salvation truck doesn't make weekly pickups, let alone the clean air truck. ⑤ When a public opinion poll in 1990 asked people what they had done in connection with environmental problems, 80 to 85% answered that they or their households had participated in various aspects of recycling; no other significant steps had been taken by the majority of respondents. ⑥ Like the drunk looking for his wallet under the lamppost, we may focus on recycling because it is where the immediate tasks are best illuminated.

① When spending time at a pub or a restaurant, you might be brought a drink or a small plate of food at no charge. ② If so, you'll likely be informed that it is "on the house." ③ But where did this common phrase come from? ④ In the past, most pubs in England were located on the first floor of an inn. ⑤ Local people would often stop by these pubs. ⑥ But they also served as a place for the travelers staying on the upper floors to get food and a drink. ⑦ The entire business, consisting of the inn and the pub, was therefore referred to as the "house." ⑧ Often, the owners of these pubs would offer a free drink to customers who were staying upstairs at the inn. ⑨ Because of this, the phrase has come to mean a gift from the business.

① Researchers suggested an interesting theory about the reason why expensive shops are designed to be such calming places. ② In an experiment, 670 people were put into two different states of relaxation: quite relaxed or less relaxed. ③ They were then asked how much they would pay for a certain digital camera. ④ The quite-relaxed subjects offered 11% more than their less-relaxed counterparts. ⑤ This was replicated in other tests, showing that when it is relaxed, the brain focuses on the benefits the product would provide. ⑥ As another example, think of a person shopping for an expensive car. ⑦ A relaxed shopper may picture the comfort of being in the car and make a decision based on that. ⑧ A less-relaxed person, though, would be practical, focusing on necessities and avoiding painful future costs.

① The basis of all humor is really the same: mixing ideas that don't belong together. ② This surprises you and makes you laugh. ③ It may be a situation:. ④ The teacher sits down solemnly in front of the class of 12-year-olds, but one of them has put a pin on his chair;. ⑤ He jumps up screaming in pain. ⑥ Why is that funny? ⑦ A person of authority suddenly looks like a weak and ordinary human being. ⑧ It may also be a game with words:. ⑨ "Doorman, can you call me a taxi?" ⑩ "OK, you're a taxi." ⑪ Why is that funny? ⑫ The doorman has interpreted "call me" in a different sense, such as "call me John." ⑬ Finally, it may be a continuous situation in a comic novel:. ⑭ In the Spanish novel Don Quixote, the hero (Don Quixote) dreams of battle and glory, but his servant Sancho Panza dreams of food and wine;. ⑮ This contrast is used to create a humorous effect throughout the book.

① We often try to find happiness outside of ourselves by pursuing money, new clothes, or praise. ② Although getting them usually makes us feel good, it's a feeling that doesn't last for long. ③ We soon begin to need more and more of these things in order to feel good. ④ In other words, the more we look for happiness outside of ourselves, the harder it becomes to find it. ⑤ Psychiatrists even have a name for this condition: "hedonic adaptation." ⑥ It is considered to be one of the main reasons why we are often unsatisfied with our lives, despite all of the things we have acquired. ⑦ Whether we want gold, good grades, popularity, or attention, searching for external rewards is guaranteed to lead us away from happiness.

① It is clear that children expand their vocabularies by reading. ② They encounter more words when reading, which enables them to learn more words. ③ But is it better to read a variety of short stories on different subjects, or should a single topic be focused on over a longer period? ④ According to a new study, staying with one topic is the better way to improve one's vocabulary. ⑤ This is due to the fact that new words are presented in a familiar context, which makes it easier to learn their meaning. ⑥ Imagine that you read a story about animals to your children. ⑦ The words they learn will be repeated if you continue to read about animals every day. ⑧ The more frequently they see the words used in the stories, the more likely it is that they will remember the words. ⑨ For this reason, if your goal is to improve your children's vocabulary through reading, you should concentrate on a subject long enough for it to become familiar.

① People often use the old saying "Blood is thicker than water" to say that your connection to family is more important than your loyalty to anything else. ② However, this meaning is quite different from what the original saying implied. ③ Back then, it was used to emphasize the reliance between soldiers. ④ The blood mentioned in the saying referred to the bleeding of warriors who suffered together on the field of battle, and the water meant "the water of the womb." ⑤ The saying was also used to refer to the practice of using blood to finalize a contract. ⑥ When two people mixed their blood together, it was believed that their agreement was permanent and could never be broken. ⑦ Over time, however, the meaning of "Blood is thicker than water" has changed to better fit our modern culture.

① Patients should be aware that there can be differing views among specialists about who should be treated for various conditions. ② For example, expert committees in Europe and the United States set different guidelines about when to treat high blood pressure. ③ The group of American experts believed that for mild elevation of blood pressure the benefits exceeded the risks from treatment. ④ They wrote guidelines suggesting that patients with mild blood pressure elevation take medicine. ⑤ But in Europe, an expert committee with access to the same scientific data set different guidelines that don't advise treatment for mild elevation of blood pressure. ⑥ In Europe, people with the same symptoms would not be encouraged to take medicine. ⑦ Different groups of experts can disagree significantly about what is "best practice."

① In the medical profession, technology is advancing so fast that questions of law and ethics cannot be discussed and answered fast enough. ② Most of these questions involve ending or beginning a human life. ③ For example, we have the medical ability to keep a person technically "alive" for years on machines after he or she is "brain dead," which means that the brain has stopped functioning. ④ But is it ethical to do this? ⑤ And what about the alternative? ⑥ In other words, is it ethical not to keep a person alive even if we have the technology to do so? ⑦ Nobody can answer these questions with certainty.

① Should schools watch their students' health? ② The answer is yes, since not all students are recipients of good guidance at home. ③ Because of the central role they play in children's lives, schools have the power to promote healthy lifestyles by emphasizing nutrition, exercise, and education. ④ Furthermore, by sensitively dealing with the first warning signs of weight issues in young children, schools can help students tackle problems that might develop into eating disorders or obesity later in life. ⑤ In an ideal world, this would be a job that parents would perform, but realistically, this task often falls into the hands of our schools. ⑥ It's time we acknowledged that.

① Sir Henry Stanley explored the Congo River on a journey that was sponsored by Belgium's King Leopold in the 1870s. ② Throughout his voyage, Stanley stopped at ports along the way to make treaties with local political leaders. ③ As a result, upon his return to Europe, he was able to present King Leopold with a gift of land more than eighty times the size of Belgium. ④ Tragically, the Belgian Congo was severely exploited under Leopold, and the Congolese were forced into slave labor. ⑤ Leopold came to symbolize the worst traits of humanity: greed, self-indulgence, and violence. ⑥ The king received international criticism for his tyranny, which made him try to earn the support of the Congolese people by spending generously on public works projects. ⑦ Nevertheless, people continued to despise him, and eventually he was forced to relinquish his holdings in the Congo.

① What is a genius? ② Is it simply someone who is able to answer every question on a test? ③ Actually, people who are considered to be geniuses are more than just abnormally smart. ④ In addition to being extremely intelligent, they are also highly creative and imaginative, capable of thinking freely and questioning the limits of what other people believe to be possible. ⑤ Apparently, one of the key characteristics shared by geniuses is their ability to focus on seemingly unimportant information. ⑥ The majority of geniuses pay attention to the kinds of details that most other people deem useless and simply ignore. ⑦ Because of this, their perspectives are richer and somewhat more complex, and they remain open to new possibilities. ⑧ Now think about all the smart people you know. ⑨ Are any of them true geniuses?

① For years after a tragic event occurs, we will be able to remember exactly where we were and what we were doing when we heard the news, which is a phenomenon referred to as a "flashbulb memory." ② The generation that grew up in the 1960s, for instance, has a collection of flashbulb memories about the assassinations of President John F. Kennedy and Dr. Martin Luther King Jr. ③ The unexpected death of a well-known figure, however, is not the only event that will trigger the creation of a flashbulb memory. ④ The death of a loved one or a national tragedy like the September 11 attacks may also deeply affect us and result in a flashbulb memory.

① Some people criticize the attitude of researchers and raise doubts about the power of science. ② This may be because many researchers fail to look at the big picture, choosing instead to focus on their own fields. ③ However, when we take a step back and carefully look at how science affects society, it becomes clear that science has played a big role in human advancement. ④ This is not only because of the many inventions it has led to, but also because of the basic ideas that make up its foundation. ⑤ Investor Peter Thiel agrees that progress in science is crucial for the human race, and American philosopher John Dewey even proposed that science is the foundation of democracy. ⑥ People who practice science trust in equality. ⑦ They desire truth and progress. ⑧ Greed, prejudice, and other outside influences are unwelcome in science. ⑨ It demands total honesty and a willingness to accept the most logical argument.

① Air resistance, the principle that makes parachutes work, can be observed in a simple experiment. ② Gather up a sheet of paper and a coffee cup, hold them at the same height, and release both objects at the same time. ③ What you'll observe is that the coffee cup plummets to the ground. ④ On the other hand, the sheet of paper descends slowly and gently. ⑤ The heavy cup, since it easily parts the air molecules in its path, falls to the ground quickly, while the sheet of paper, too light to push away the air molecules, is greatly slowed on its way to the ground. ⑥ Likewise, when a parachute is deployed, because it is made of very light material, its fall is slowed by the air molecules in its path.

① Malaria once infected nine out of ten people in North Borneo. ② In 1955, the World Health Organization (WHO) began spraying a certain pesticide to kill malaria-carrying mosquitoes. ③ The program was so successful that the dreaded disease was almost eliminated from the island. ④ Other things happened, however, that were unexpected. ⑤ The pesticide killed other insects, including flies and cockroaches, living in houses. ⑥ The islanders applauded, but then small lizards that also lived in the houses died after eating dead insects. ⑦ Then cats began dying after feeding on the dead lizards. ⑧ Without cats, rats flourished and overran the villages. ⑨ Now people were threatened by a terrible plague carried by the fleas on the rats.

① In today's marketing and advertising-soaked world, people cannot escape brands. ② The younger people are when they start using a brand or product, the more likely they are to keep using it for years to come. ③ But that's not the only reason companies are aiming their marketing and advertising at younger consumers. ④ As James U. McNeal, a professor at Texas A&M University, puts it, "Seventy-five percent of spontaneous food purchases can be traced to a nagging child. ⑤ And one out of two mothers will buy a food simply because her child requests it. ⑥ To trigger desire in a child is to trigger desire in the whole family." ⑦ In other words, kids have power over spending in their households, they have power over their grandparents, and they have power over their babysitters. ⑧ That's why companies use tricks to manipulate their minds.

① It is common to see meat packaging that boasts of humane treatment and processes that minimize the suffering of the animals. ② Consumers are attracted to these labels because they are morally concerned with the way in which the meat was obtained. ③ However, a study suggests that there is another reason for using such labels. ④ In an experiment, researchers gave participants identical meat samples presented in different ways. ⑤ One was labeled as "humanely raised," and the other was said to be from a factory. ⑥ Surprisingly, the former was rated as tasting better than the latter. ⑦ Participants even rated the humane-labeled meat as superior to the factory-labeled samples in terms of smell and look. ⑧ These results show that there is a lot more to how consumers perceive a product's taste than simply its ingredients.

① Two people with similar diets may have very different physical appearances, even if their other activities are also comparable. ② Researchers at Yale University may have found the reason for this. ③ The scientists discovered variances in the stomach signaling systems of rats. ④ Indeed, the intensity with which the rats' stomachs sent signals when they were full varied from rat to rat. ⑤ In some cases, the signal was dull—. ⑥ This caused the rats to continue to eat even after they were full. ⑦ This type of behavior eventually leads to obesity, which suggests that human obesity may be linked to more than just personal choices. ⑧ Professor Tamas Horvath argues that the nature of the connection between their stomachs and their brains might be causing certain people to consume more than they should.

① When shooting a basketball, it is desirable to make the ball spin in a backward direction. ② However, this is not done to use air resistance to make the ball curve, as it is in the sport of baseball. ③ When shot at the hoop, a basketball moves too slowly for this to occur. ④ Therefore, its path is not affected by the spin. ⑤ So what is the purpose? ⑥ If the ball is thrown directly through the hoop, there is none. ⑦ But if it hits the backboard or the rim of the hoop first, this backspin will cause a change in velocity in the opposite direction. ⑧ Therefore, rather than bouncing away at full strength, the ball will remain near the hoop. ⑨ This makes it more likely that it will bounce once or twice and then fall through the net.

① In an experiment, researchers placed participants in groups. ② Some were randomly made team managers, a position of power, while the rest were assigned the low-power role of worker. ③ After completing a group activity, each participant was asked to make a series of decisions. ④ They were given the choice of receiving $120 now or a larger amount of money in one year. ⑤ This amount started at $137 and was gradually increased up to $240. ⑥ The researchers found that the people assigned low-power roles were less willing to postpone their rewards than the people assigned high-power roles. ⑦ They concluded that people who have a lot of power are more confident about their future and therefore do not mind waiting for a reward. ⑧ People with little power, on the other hand, face an uncertain future and prefer an immediate reward, even if it is smaller.

① Just as she was thinking she would have to stop soon to rest, she noticed some light coming through the trees in the distance, and she realized she must be coming to a clearing. ② As she pushed through the last of the vines and stared into the blinding light, she saw an Indian village. ③ In the center stood a long hut. ④ There were also other, smaller huts as well. ⑤ A fire was burning in the middle of the clearing, which was about 200 meters wide. ⑥ But there was no one there. ⑦ She stood hiding in the shadows of the jungle, knowing that she must have been trailed for many miles by the Indians moving like ghosts through their own underworld. ⑧ She felt she was being watched by many eyes.

① I watched the beautiful shoreline of the strange land as it came into view. ② After spending so much time aboard the ship, I finally saw the land of limitless opportunity. ③ It was as though an unknown world were inviting me to explore it, and I had no intention of declining the invitation. ④ I had accepted a job working as a nurse at a medical clinic recently established in a rural area inland. ⑤ It had always been my dream to bring modern medicine to poor villagers, and now the dream was on the verge of coming true. ⑥ The distant mountains emerging from the morning mist welcomed me with endless promises. ⑦ Somewhere out there, my destiny awaited me.

① We managed to get a roaring fire going in spite of the icy wind. ② Shivering, we crawled into our tent and talked until the wind made it hard to hear. ③ Eventually I dropped off into sleep, but I was suddenly awakened by Caleb, who had a look of horror on his face. ④ Then I felt the heat of the flames all around us. ⑤ A spark from the campfire had ignited our tent, and now it was collapsing on us. ⑥ Blindly, I clawed at the door zipper. ⑦ When I finally made it out, I saw that Caleb was still trapped inside. ⑧ Grabbing him by his burning jacket, I dragged him to the lake.

① One night, while Eric was watching television, he thought he heard a knock at the door. ② But when he opened it, he saw only a few dried leaves blowing in a cold breeze. ③ Then, from above him, the knocking sound echoed down. ④ The attic! ⑤ He moved slowly to the kitchen, where he picked up a flashlight. ⑥ His hand shook so much that its light jumped back and forth in front of him. ⑦ He began to climb the stairs. ⑧ It seemed to take an hour to walk up them. ⑨ Now he could see the attic door—and hear more noises coming from it. ⑩ There was a scratching sound, as if something was trying to get out. ⑪ He hesitated. ⑫ At that moment, the door flew open. ⑬ Eric jumped backwards and almost fell as his terrified cat, Calvin, ran past him. ⑭ "Calvin! ⑮ How did you get in there?" ⑯ Eric shouted. ⑰ He sighed and went back downstairs.

① With glittering snowflakes swirling around him, Michael stamped his boots on the mat and went inside. ② The smell of cinnamon met him, and he heard bits of talk and laughter from the kitchen, where his parents were baking. ③ He hung up his outdoor things and moved to the living room, taking his favorite seat near the fireplace. ④ Lying back against the arm of the chair, he looked out the window into the tree branches outside. ⑤ They were heavy with snow and bright red berries. ⑥ A little brown bird hopped here and there among them. ⑦ It sent tiny avalanches falling from twig to twig and then stopped to fluff up its feathers and stare back at Michael with sparkling eyes. ⑧ As he watched the bird, his own eyes began to close, and dreams of sledding and hot chocolate and long talks with his grandfather filled his head.

① Every time Emma looked at her sister Victoria, she felt proud simply because of how beautiful she was. ② Victoria was tall and plump with deep brown hair, and Emma loved her more than anyone else in the world. ③ Today, she was thinking of all the lovely afternoons they had spent singing together. ④ The music started right on time, and everyone looked to the back of the room. ⑤ Emma gasped—her sister was more beautiful than ever in her white dress. ⑥ Victoria walked gracefully to the front of the hall and smiled at Emma. ⑦ Then, to Victoria's surprise, the music changed. ⑧ Emma stepped forward and began to sing. ⑨ Tears came to Victoria's eyes as she recognized the familiar words of their favorite childhood song. ⑩ Emma too began to cry as she sang and remembered all their happy times together.

① The skaters stood on the ice, preparing to dash forward. ② "Ready!" ③ The command echoed across the rink. ④ Andre leaned forward, his heart pounding. ⑤ As a loud "boom!" ⑥ rang out, the athletes sprang away from the starting line and went flying around the track. ⑦ There were three skaters in front of him. ⑧ At a turn, he slid easily around the last one and held his place at third. ⑨ Two more laps passed, and he tried to push forward, but his rivals didn't let him do it. ⑩ The seconds flew by, and the finish line was approaching. ⑪ With all his effort, Andre moved in for another attempt. ⑫ At the same moment, the second-place skater tried to pass on the inside. ⑬ He miscalculated. ⑭ He brushed the leader, and instantly they both fell. ⑮ Andre rocketed across the finish line. ⑯ Around him, the crowd cheered his name.

① For a moment, when she heard the loud banging at the door, she allowed herself to think it was the postman knocking in a big hurry. ② But a commanding voice boomed through the house an instant later. ③ "Police inspection! ④ Open up!" ⑤ As her uncle moved towards the door, he gave her a look she knew well. ⑥ She didn't need his reminder. ⑦ She was already rushing down the hall silently. ⑧ Her brothers were in the back room. ⑨ As soon as they saw her, they knew what was happening. ⑩ They followed without a sound. ⑪ Together, they all slipped into the hidden space behind the bookcase and fastened each lock. ⑫ And then they waited. ⑬ Outside, heavy footsteps moved here and there, sometimes closer, sometimes farther away, and harsh voices shouted orders. ⑭ The siblings held still, breathing as little as possible, listening for their uncle's signal.

① Dr. Paul Odland and his friend Bob travel frequently to South America, where they provide free medical treatment for disabled children of poor families. ② One day, they went to a local marketplace. ③ Paul wanted to buy some souvenirs, and he spotted a carving that he liked. ④ The non-English-speaking seller was asking 500 pesos for the carving. ⑤ With Bob acting as interpreter, Paul offered 300 and his opponent proposed 450. ⑥ The bargaining in the noisy market became spirited, even intense, with Paul stepping up his price slightly and the seller going down slowly. ⑦ The pace increased so fast that Bob could not keep up with the back-and-forth interpretation. ⑧ Meanwhile, observing the seller carefully, Paul sensed something wrong in Bob's interpretation. ⑨ In fact, the seller had gone below Paul's last offer. ⑩ When Paul raised his doubt, Bob instantly recognized the error and corrected his interpretation. ⑪ At length, they settled the deal, and he was delighted to purchase the carving at a reasonable price and thanked Bob.

① Jenny learned from her mother how to prepare a roast. ② When she was a young child, she would watch her mother always cut off one end of the roast before cooking it. ③ Later, she did the same thing whenever she prepared a roast. ④ But one day, a question occurred to her:. ⑤ What's the reason for this? ⑥ When she asked her mother, she simply replied that she had learned it by copying her own mother. ⑦ So Jenny asked her grandmother, who explained that the roasting pan she had owned when she was younger was too small. ⑧ Therefore, she had to cut off one end of the roast to make it fit. ⑨ Now that she had a larger pan, she no longer had to do this. ⑩ But both Jenny and her mother had been following this pointless routine for years!

① An old man was riding on a train with his adult son. ② When the train pulled away from the station, the other passengers watched curiously as the son clapped his hands in excitement. ③ Pressing his face against the window, he began to shout out the things the train passed. ④ "Look, Papa!" ⑤ he shouted, "What's that? ⑥ Is that a tree?" ⑦ The old man just smiled and nodded. ⑧ The other passengers looked away, embarrassed by the younger man's behavior. ⑨ Finally, one of them leaned over and asked the old man if he had considered taking his son to see a doctor. ⑩ "Actually, we're on our way home from the hospital," said the old man. ⑪ "My son had an operation on his eyes and can see for the first time in his life."

① Scientists have discovered that bacteria naturally found in polluted water can help in the cleanup of water when vinegar is added. ② The addition of vinegar to the contaminated water stimulates the bacteria in the water. ③ Then those bacteria convert the toxins in the water into salt, producing oxygen as they work. ④ Best of all, they do not require sunlight or air, and therefore can function even in underwater and underground environments. ⑤ Some researchers are hopeful that they could be used in enclosed spaces, such as mines or spacecraft, to digest waste products and generate oxygen. ⑥ They are also eager to see how the bacteria deal with radioactive waste. ⑦ It is hoped that they may be able to help us clean up radioactive sites.

① A small white horse was not accustomed to sharing the sweetest grasses in his valley with any other animals. ② One day when an arrogant stag showed up and claimed he had a right to graze there, the little white horse was irritated enough to turn to a man he knew and ask if he could help. ③ The man explained that he would need to put a bridle in the horse's mouth and ride on his back. ④ Desperate to drive the stag away, he agreed to the man's terms without much thought. ⑤ Due to the help of the man, the horse could get rid of the stag from his valley. ⑥ Once the stag was gone, he was very satisfied. ⑦ However, it didn't take long for him to realize that he had sacrificed the freedom he used to enjoy.

① For Jena, every Saturday was a battle with her younger sister, Mimi. ② She understood that her parents needed a break from the little monster. ③ But she didn't know why they made her take Mimi to the park. ④ "She loves spending time with you," her mother always said happily. ⑤ Jena didn't understand what she was talking about. ⑥ Mimi would complain that it was cold and she didn't want to go. ⑦ "Well, where are your gloves？" Jena would ask. ⑧ Mimi would tell her she had left them at school. ⑨ "You can borrow mine," Jena would say and drag Mimi out the door. ⑩ For some reason, Jena did not appreciate the smile on her mother's face as she called out, "Have fun!" ⑪ from the window. ⑫ She simply hoped that Mimi would play quietly once they got to the park so she could do her homework in peace.

① Russian physiologist Ivan Pavlov is credited with creating the first instance of behavioral conditioning by triggering dogs' salivation with a bell. ② Now, Japanese scientists have replicated this reaction in cockroaches. ③ They managed to make the insects respond to certain smells, such as peppermint and vanilla. ④ To achieve this, they gave the cockroaches a sugary liquid right after releasing these scents. ⑤ They did this repeatedly over a period of time and then measured the cockroaches' salivation behavior when various smells were placed on their antennae. ⑥ What they found was that the cockroaches began to salivate when exposed to vanilla and peppermint. ⑦ However, when a different odor was used, they did not have the same reaction. ⑧ Thus, the researchers successfully conditioned the animals to physiologically respond to stimuli that were previously irrelevant, just like Pavlov's dogs responded to the bell.

① Henry likes to plant flowers. ② It sounds like a normal hobby, but what makes it unusual is that he plants them in weird places. ③ Every spring, he is busy turning land covered in garbage into beautiful fields of flowers. ④ Henry covers the land in seeds, using a long reed that he carries with him to blow them into areas which are difficult to reach. ⑤ Some people make fun of him, but he never lets it bother him. ⑥ The other day, the owner of a lot tried to chase him away. ⑦ Henry left, but returned days later to finish the job when no one was around. ⑧ Imagine the owner's surprise months later when he saw colorful flowers growing in the shape of a giant letter "H" in his lot!

① If you had been living in Russia when Peter the Great ruled the country, you would have had to pay a special tax just to have a beard. ② Before that, Russian men wore long beards for centuries. ③ Not only was it tradition, but it also showed the country's religious views on manhood. ④ Many Russians believed it was dishonorable to shave off a beard. ⑤ However, when Peter the Great returned from a trip to Europe, he wanted to change this custom. ⑥ Thinking that European customs were superior to Russian customs, Peter ordered all of his citizens to cut off their beards so that Russian society and culture would be more European. ⑦ Russian men found it hard to adjust to this new custom, so Peter imposed a tax on beards and came up with a "beard token" to help bearded men pay the tax more easily. ⑧ The tax lasted until 1772, when it was abolished due to massive opposition.

① The highly populated capital city of Mexico is sinking, descending about six inches every year. ② The root of the problem lies in the city's geography, as it is built in a basin that was once a huge lake. ③ Since 1519, people have drained water from underground to meet the needs of the city's enormous population. ④ As the water is pumped up, the soil becomes more compressed, which causes the city to inch lower and lower every year. ⑤ This is accelerated when tall buildings are constructed and people seeking jobs in the city suddenly increase. ⑥ If this trend were to continue unchecked at its current rate, the enormous metropolis would be destroyed at some point in the not-too-distant future.

① The Henry Ford Museum offers visitors some of the most interesting attractions to be found in the country. ② You can visit Thomas Edison's workshop or a courtroom used by Abraham Lincoln. ③ Visitors may not only take a ride on a steam train but also enjoy a Model T automobile. ④ What draws so many visitors is the fact that these exhibits and others are not replicas. ⑤ They are the real thing. ⑥ The museum is home to twelve railroad locomotives, more than a hundred classic cars, some silver items made by Paul Revere, and Henry Ford's first car, the Ford Quadricycle, which he invented in 1896. ⑦ If Ford himself had not built the museum, some important artifacts from American history might not exist today.