Passage Three

      As recently as three decades ago, many Americans believed that using credit was an unwise and dangerous way to pay for what they bought. Some even thought that owing money to a store or a credit company was something to be ashamed of. Good citizens, they believed, always bought what they wanted with real money and they paid the full price immediately.　
      Today, however, all that has changed. Credit, as some observers have noted, has become a way of life in the United States. More and more Americans now are depending on those small pieces of plastic, credit cards, to pay for large purchases such as televisions, record players or furniture. Many people today would consider it unusual not to use a credit card to pay for a costly restaurant dinner, a hotel room or an airline trip. And there are some situations in which Americans must have credit cards. If they want the temporary use of a car, for example, they first must give the car rental company the number of their credit card. That number is considered a guarantee that they will return the car and pay for using it.

      Credit cards offer two major services to Americans. First of all, they are easier and safer to carry than large amounts of money. Second, they permit people to borrow, to have the immediate pleasure of owning something, even if they do not have enough money to pay for it at the time. With credit cards people pay for goods or services at the end of each month instead of when they buy them. And when the time does come to pay, most credit cards offer people a choice. They can pay all of what they owe for the month or they can just pay usually between 5 and 10 percent of what they owe.​

        Socrates is often referred to as one of the founders of Western philosophy, and yet he wrote nothing, established no school, and held no particular theories of his own. What he did do, however, was frequently ask the questions that interested him, and in doing so developed a new way of thinking. This method proceeds(展开)as a dialogue between opposing views, and it earned him many enemies in Athens, where he lived.
        As a young man, Socrates is believed to have studied natural philosophy, looking at the various explanations of the nature of the universe, but then became involved in the politics of the city-state and concerned with more down-to-earth moral issues, such as the nature of justice.
        However, he was not interested in winning arguments, or arguing for the sake of making money. Nor was he seeking answers or explanations. He was simply examining the basis of the concepts we apply to ourselves (such as “good” , “bad”, and “just” ), for he believed that understanding what we are is the first task of philosophy.
        He was sentenced to death on charges of corrupting the young with bad ideas. But he also had many followers, and among them was Plato, who recorded Socrates’ ideas in the written works, called dialogues, in which Socrates sets about examining various ideas.
        Socrates' central concern, then, was the examination of life, and it was his cruel questioning of people’s most valued beliefs (largely about themselves) that earned him his enemies—but he remained committed to his task until the very end. According to the account of his defense at his trial, Socrates chose death rather than face a life of ignorance: “The life which is unexamined is not worth living.”

        Sound sleep occurs when one’s internal clock is regulated. Circadian rhythms(生理节奏)can become compromised quite easily. Many people with sleep troubles tend to vary bedtimes. To avoid this common problem, sleep sufferers should go to bed and wake up at the same time every day. To help improve circadian rhythms, sufferers should enjoy 15 minutes of sun exposure the first thing in the morning.
        A bedtime routine can help prevent insomnia(失眠). One hour before bedtime, one should lower the lights and relax. Reading a book or listening to calm music can help prepare the body for a good night’s sleep. Taking a warm, candlelit bath or drinking a cup of warm milk can also help you prepare for deep sleep at night.
        Stress can have a bad effect on the body and the ability to sleep. A daily exercise routine can help lower the body’s stress naturally. One can also manage stress by writing diaries. Writing diaries can help people express their anxieties, plan for the future and improve sleep. Other ways to lower stress include deep breathing exercises and progressive muscle relaxation.
        The light sending out from computers, cell phones, tablets and televisions can cause sleep problems. Therefore, these items should be turned off at least an hour before bedtime. Additionally, lowering the backlight on these electronic devices earlier in the evening can help you fall asleep faster and stay asleep longer once bedtime arrives.
        A perfect bedroom invites sweet sleep. Most people sleep better in a cool, dark, and quiet room. Lower the temperature in the room to 16~20 degrees for a peaceful night’s sleep. A dark room can be accomplished by installing light blocking curtains or wearing a sleep mask. Noise can be reduced with either earplugs or a white noise machine. Finally, a comfortable mattress(床垫)and pillows are essential to a good night’s sleep.

Passage Two

      ​There were many different cultures in the ancient world, but the two that had the most influence on European and American civilizations were the Greek and the Roman. Often these two cultures are lumped together in our minds, as if they were really exactly alike. But that is not the case. In many ways the Greeks and the Romans could not have been more different. 

      The Greeks were truly democratic, often without a single leader but instead governed by a group of men chosen by the people. The Romans were semi-democratic. They had a governing Senate, but the political power was mostly or completely in the hands of a single emperor. 

      Both cultures were great builders. But the construction interests of the two cultures were also different. The Greeks tended to be more artistic. Their buildings were well constructed and they were especially interested in temples, columns, and decorative forms. The Romans, on the other hand, were more engineers than artists. They concentrated their efforts on urban planning, well-functioning water pipes, and the best roads.
      Only in cooking and eating habits are the two cultures really similar. Both peoples ate very well indeed: lots of fish, fresh vegetables and fruits, healthy meals, holding at the same time long discussions and tasting excellent wines.
      In fact, it would probably be fair to say that they both loved life in their warm,sea-oriented climates and they both lived a full life.

Passage Four

      At the 1893 Columbian Exposition, a World Fair held in Chicago, chocolate-making machinery made in Germany was displayed. It caught the eye of M. S. Hershey, who saw the potential for chocolate. He installed chocolate machinery in his factory in Lancaster, and produced his first chocolate bars in 1894.
      Other Americans began mixing in other materials to make up new candy bars throughout the end of the 1890s and the early 1900s. But it was World War I that really brought attention to the candy bar.
      The U. S. Army Quartermaster Corps requested various American chocolate manufacturers to provide 20 to 40-pound blocks of chocolate to be shipped to quartermaster bases. The blocks were cut into smaller pieces and distributed to American soldiers in Europe. Eventually the task of making smaller pieces was turned back to the manufacturers. By the end of the war when the soldiers arrived home, the American candy bar business was assured. Why? Because the returning soldiers had grown fond of chocolate candy and wanted more of the same. As a result from that time on and through the 1920s, candy bar manufacturers became established throughout the United States, and as many as 40, 000 different candy bars appeared on the scene.

      The original candy bar industry had its start on the eastern coast in such cities as Philadelphia, Boston, and New York. The industry soon spread to the Midwest because shipping and raw materials such as sugar, corn syrup, and milk were easily available. Chicago became the seat of the candy bar industry and is even today an important base.​

      ​Coconut (椰子) is an unusual food for many reasons. It is one of the largest edible seeds produced by any plant. Its unusual contents also make it unique in the seed world--it consists of both"meat" and "water" inside. The coconut meat is the white substance with which we are all familiar, as it is used extensively for cooking and flavorings; the coconut water is a white and sweet liquid. 

      Portuguese (葡萄牙) explorers gave the nut its name in the 15th century, referring to it as coco, meaning "ghost" in their language. The outside appearance of coconuts reminded them of a ghost's face, and the tree has had that name ever since. 

      The coconut has varied uses. It is used to make various cooking oils for fast-food restaurants around the world to make diet materials. The coconut fluid is a favorite drink in hot climates, providing a cool and refreshing beverage right off the tree. This water is also used by manufacturers of various sports drinks. Even the shell itself has many uses, including animal food and fertilizer.
      Yet the coconut is also useful in many ways that have nothing to do with food. Coconut oil is used for cosmetics (化妆品), medicines, and so on. Dried coconut shells are used in many countries as a tool for shining wood floors. The shells are also used for shirt buttons, and are commonly found on Hawaiian clothing. They are even used for musical instruments and bird houses.
      And all these are only some of the uses found for the coconut fruit. The coconut tree, which produces the nut,also produces many useful things. It' s no wonder that the coconut tree has been taken as "the tree of life".

​

        The banana "tree" is actually not a real tree. This is because there is no wood in the stem(树干)rising above the ground. The stem is made up of leaves growing very close together, one inside the other. The leaves spread out at the top of the stem and rise in the air.
        Banana plants need a lot of care and attention. They must be provided with water if the normal rainfall doesn’t supply enough. The area around the plants must be kept free of weeds(杂草)and grass.
        About nine or ten months after planting, a flower appears on the banana plant. This flower is at the end of a long stalk(茎), which grows from the base up through the center of the stem and turns downward when it comes out from the top. Small bananas form on this flower stalk as it grows downward. Bananas really grow upside down. As the small bananas form on the stalk, they point downward, but as they grow they turn and point upward.
        Bananas are harvested while they are still green. Even when they are to be eaten where they are grown, they are not allowed to ripen on the plant. A banana that turns yellow on the plant loses its taste.

        On a dry and cold Friday afternoon last October, Sharon Seline exchanged text messages with her daughter who was in college. They “chatted” back and forth, with the mom asking how things were going and the daughter answering positively followed by emoticons(表情符)showing smiles, b-i-g smiles and hearts.
        Later that night, her daughter attempted suicide.
        In the days that followed, it came to light that she’d hidden herself in her dorm, crying and showing signs of depression—a completely different reality from the one that she conveyed in texts and Facebook posts.
        As human beings, our only real method of connection is through real communication. Studies show that only 7% of communication is based on writing and speaking. The majority of 93% is based on body language. Indeed, it’s only when we can hear a tone of voice or look into someone’s eyes that we’re able to know when “I’m fine” doesn’t mean they’re fine at all.
        This is where social media gets risky.
        With modern technology, anyone can hide behind the text, the e-mail, or the Face book post, projecting any image they want and creating a false image of their choosing. They can be whoever they want to be. And without the ability to receive body language, their audiences are none the wiser.
        This presents a paradox which doesn’t exist before. With all the powerful social technologies at our fingertips, we are more connected—and potentially more disconnected—than ever before.
Every relevant metric(衡量标准)shows that we are interacting at a great speed and frequency through social media. But are we really communicating? With 93% of our communication context(语境)lost, we are now attempting to establish relationships and make decisions based on phrases or emoticons, which may or may not accurately represent the truth.

        How can we get rid of garbage? Do we have enough energy sources to meet our future energy needs?

        These are two important questions that many people are asking today. Some people think that man might be able to solve both problems at the same time. They suggest using garbage as an energy source, and at the same time it can save the land to hold garbage.

        For a long time, people buried garbage or dumped it on empty land. Now, empty land is scarce. But more and more garbage is produced each year. However, garage can be a good fuel to use. The things in garbage do not look like coal, petroleum, or natural gas; but they are chemically similar to these fossil fuels. As we use up our fossil-fuel supplies, we might be able to use garbage as an energy source. Burning garbage is not a new idea. Some cities in Europe and the United States have been burning garbage for years. The heat that is produced by burning garbage is used to boil water. The steam that is produced is used to make electricity or to heat nearby buildings. In Paris, France, some power plants bum almost 2 million metric tons of the city’s garbage each year. The amount of energy produced is about the same as would be produced by burning almost a half million barrels of oil.

        Our fossil fuel supplies are limited. Burning garbage might be one kind of energy source that we can use to help meet our energy needs. This method could also reduce the amount of garbage piling up on the earth.

      There is a popular belief among parents that schools are no longer interested in spelling. No school I have taught in has ever ignored spelling or considered it unimportant as a basic skill. There are, however, vastly different ideas about how to teach it, or how much priority it must be given over general language development and writing ability. The problem is, how to encourage a child to express himself freely and confidently in writing without holding him back with the complexities of spelling?
      If spelling becomes the only focal point of his teacher's interest, clearly a bright child will be likely to "play safe". He will tend to write only words within his spelling range, choosing to avoid adventurous language. That's why teachers often encourage the early use of dictionaries and pay attention to content rather than technical ability.
      I was once shocked to read on the bottom of a sensitive piece of writing about a personal experience: "This work is terrible! There are far too many spelling errors and your writing is illegible." It may have been a sharp criticism of the pupil's technical abilities in writing, but it was also a sad reflection on the teacher who had omitted to read the essay, which contained some beautiful expressions of the child's deep feelings. The teacher was not wrong to draw attention to the errors, but if his priorities had centered on the child's ideas, an expression of his disappointment with the presentation would have given the pupil more motivation to seek improvement.

      In ancient times wealth was measured and exchanged in things that could be touched: food, tools, and precious metals and stones. Then the barter system was replaced by coins, which still had real value since they were pieces of rare metal. Coins were followed by fiat money, paper notes that have value only because everyone agrees to accept them.
     Today electronic monetary systems are gradually being introduced that will transform money into even less tangible forms, reducing it to a series of "bits and bytes", or units of computerized information, going between machines at the speed of light. Already, electronic fund transfer allows money to be instantly sent and received by different banks, companies, and countries through computers and telecommunications devices.

        How can we get rid of garbage? Do we have enough energy sources to meet our future energy needs?

        These are two important questions that many people are asking today. Some people think that man might be able to solve both problems at the same time. They suggest using garbage as an energy source, and at the same time it can save the land to hold garbage.

        For a long time, people buried garbage or dumped it on empty land. Now, empty land is scarce. But more and more garbage is produced each year. However, garage can be a good fuel to use. The things in garbage do not look like coal, petroleum, or natural gas; but they are chemically similar to these fossil fuels. As we use up our fossil-fuel supplies, we might be able to use garbage as an energy source. Burning garbage is not a new idea. Some cities in Europe and the United States have been burning garbage for years. The heat that is produced by burning garbage is used to boil water. The steam that is produced is used to make electricity or to heat nearby buildings. In Paris, France, some power plants bum almost 2 million metric tons of the city’s garbage each year. The amount of energy produced is about the same as would be produced by burning almost a half million barrels of oil.

        Our fossil fuel supplies are limited. Burning garbage might be one kind of energy source that we can use to help meet our energy needs. This method could also reduce the amount of garbage piling up on the earth.

      Animals have different ways of protecting themselves against wintertime weather. Some animals grow heavy coats of fur or feathers, while others dig into the ground to find a warm wintertime home.
      Some animals spend the winter in a deep sleep because by going to sleep they avoid the time of the year when food is scarce and the temperatures are low. Their sleep is known as hibernation.
      There is much about hibernation that puzzles scientists. For example, they are wondering how hibernation came into being. Some scientists have explored the possibility that animals release a chemical that starts them hibernating.
      One thing that scientists are certain about is that animals hibernate only when it is cold. Hibernation is a seasonal practice.
      Some animals that fall into a wintertime sleep are not true hibernators because they spend only a part of the cold season asleep. Bears, for example, can easily be awakened from their winter nap. They are not true hibernators.
      Sometimes it is difficult to determine whether a particular animal is a true hibernator. For example, some mice hibernate, but others do not. The same is true of bats. Some of them hibernate. Others do not.

     Space is a dangerous place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through, and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation. But their spacesuit or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.
     Radiation is the greatest known danger to explorers in space. The unit of radiation is called "rem". Scientists have reason to think that a man can put up with far more than 0.1 rem without being damaged; the figure of 60 rems has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage—a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed (畸形的) children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and, during the outward and return journeys, the Apollo crew accumulated a large amount of rems. So far, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spent weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but no really effective ones have been found so far. 

        Most people usually traveled by ship and train which are driven by steam engine. It played an important part in many kinds of vehicles several scores of years ago. Who invented steam engine and what units could be used to measure the power of engine?
　　The word “horse-power” was first used two hundred years ago. James Watt from a worker’s family made the world first widely used steam engine. At first, he couldn’t tell people how powerful it was, because there were no units at that time. Watt decided to find out how much work one strong horse could do in one minute. He named that unit one horse-power. In this way he could measure the work of his steam engine.
　　He discovered that a horse could lift a 3300-pound weight 10 feet into the air in one minute. His engine could lift a 3300-pound weight 100 feet in one minute. Because his engine did ten times as much work as the horse, Watt called it a ten horse-power engine.

     Ideas about polite behaviour differ from one culture to another. Some societies, such as America and Australia, for example, are mobile and very open. People here change jobs and move house quite often. As a result, they have a lot of relationships that often last only a short time, and they need to get to know people quickly. So it's normal to have friendly conversations with people that they have just met, and you can talk about things that other cultures would regard as personal.
     On the other hand, there are more crowded and less mobile societies where long-term relationships are more important. A Malaysian or Mexican business person, for example, will want to get to know you very well before he or she feels happy to start business. But when you do get to know each other, the relationship becomes much deeper than it would in a mobile society.
     To Americans, both Europeans and Asians seem cool and formal at first. On the other hand, as a passenger from a less mobile society puts it, it's no fun spending several hours next to a stranger who wants to tell you all about his or her life and asks you all sorts of questions that you don't want to answer.
     Cross-cultural differences aren't just a problem for travelers, but also for people in daily life. Some societies have "universalist'' cultures. These societies strongly respect rules, and they treat every person and situation in basically the same way. "Particularist" (强调特性的) societies also have rules, but they are less important than the society's unwritten ideas about what is right or wrong for a particular situation or a particular person. So the normal rules are changed to fit the needs of the situation or the importance of the person. 

     It seems so natural to put up an umbrella to keep the water off when it rains. But actually the umbrella was not invented as protection against rain. Its first use was a shade against the sun.
     Nobody knows who first invented it, but the umbrella was used in very ancient times. Probably the first to use it were Chinese, back in the eleventh century B. C.
     We know that the umbrella was used in ancient Egypt and Babylon as a sunshade. And there was a strange thing connected with its use: it became a symbol of honor and authority. In the Far East in ancient times the umbrella was allowed to be used only by royalty or those in high office.
     In Europe the Greeks were the first to use the umbrella as a sunshade. And the umbrella was in common use in ancient Greece. But it is believed that the first persons in Europe to use the umbrella as protection against the rain were the ancient Romans.
     During the Middle Ages, the use of the umbrella practically disappeared. Then it appeared again in Italy in the late sixteenth century. And again it was considered a symbol of power and authority. By 1680, the umbrella appeared in France, and later in England.
     By the eighteenth century, the umbrella was used against rain throughout most of Europe. Umbrella have not changed much in style during all this time, though they have become much lighter in weight. It wasn't until the twentieth century that women's umbrella began to be made, in a whole variety of colors. 

        Public goods are those commodities from whose enjoyment nobody can be effectively excluded. Everybody is free to enjoy the benefits of these commodities, and one person’s utilization does not reduce the possibilities of anybody else’ s enjoying the same good.
        Examples of public goods are not as rare as one might expect. A flood control dam is a public goods. Once the dam is built, all persons living in the area will benefit—irrespective of their own contribution to the construction cost of the dam．The same holds true for highway signs or aids to navigation. Once a lighthouse is built, no ship of any nationality can be effectively excluded from the utilization of the lighthouse for navigational purposes. National defense is another example. Even a person who voted against military expenditures or did not pay any taxes will benefit from the protection afforded.
        It is no easy task to determine the social costs and social benefits associated with a public goods. There is no practicable way of charging drivers for looking at highway signs, sailors for watching a lighthouse, and citizens for the security provided to them through national defense. Because the market does not provide the necessary signals, economic analysis has to be substituted for the impersonal judgment of the marketplace.

      The first European stock exchange was established in Antwerp, Belgium(比利时) , in 1531. There were no stock exchanges in England until the 1700’ s. A man wishing to buy or sell shares of stock had to find a broker(agents) to transact his business for him. In London, he usually went to a coffee house, because brokers often gathered there. In 1773, the brokers of London formed a stock exchange.
      In New York City, brokers met under an old button-wood tree on Wall Street. They organized the New York Stock Exchange in 1792. The American Stock Exchange, the second largest in the United States, was formerly called the Curb Exchange because of its origin on the streets of New York City.
      A stock exchange is a market place where member brokers buy and sell stocks and bonds (债券) of American and foreign businesses on behalf of the public. A stock exchange provides a market place for stocks and bonds in the same way a board of trade does for commodities. The stockbrokers receive a small commission on each transaction they make.
      The stockholder may sell his stock wherever he wants to unless the corporation has some special rule to prevent it. Prices of stock change according to general business conditions and the earnings and future prospects(前景) of the company. If the business is doing well, the stockholder may be able to sell his stock for a profit. If it is not, he may have to take a loss.

      There is no creature that does not need sleep or complete rest every day.
      If you want to know why, just try going without sleep for a long period of time. You will discover that your mind and body would become too tired to work properly. You would become irritable and find it hard to think clearly or concentrate on your work. So sleep is quite simply the time when the cells of your body recover from the work of the day and build up supplies of energy for the next period of activity.
      One of the things we all know about sleep is that we are unconscious in sleep. We do not know what is going on around us. But that doesn’t mean the body stops all activity. The important organs continue to work during sleep, but most of the body functions are slowed down.
      For example, our breathing becomes slower and deeper. The heart beats more slowly, and the blood pressure is lower. Our arms and legs become limp(柔软的) and muscles are at rest. It would be impossible for our body to relax to such an extent if we were awake. So sleep does for us what the most quiet rest can not do.
      Your body temperature becomes lower when you are asleep, which is the reason people go to sleep under some kind of covers. And even though you are unconscious, many of your reflexes(习惯性思维) still work. For instance, if someone tickles(使觉得痒) your foot, you will put it away in your sleep, or even brush a fly from your forehead. You do these things without knowing it.