For centuries, explorers have risked their lives venturing into the unknown for reasons that were to varying degrees economic and nationalistic. Columbus went west to look for better trade routes to the Orient and to promote the greater glory of Spain. Lewis and Clark journeyed into the American wilderness to find out what the U.S. had acquired when it purchased Louisiana, and the Appolo astronauts rocketed to the moon in a dramatic show off technological muscle during the cold war. Although their missions blended commercial and political-military imperatives, the explorers involved all accomplished some significant science simply by going where no scientists had gone before. Today Mars looms (隐约出现) as humanity"s next great terra incognita (未探明之地). And with doubtful prospects for a short-term financial return, with the cold war a rapidly fading memory and amid a growing emphasis on international cooperation in large space ventures, it is clear that imperatives other than profits or nationalism will have to compel human beings to leave their tracks on the planet"s reddish surface. Could it be that science, which has long played a minor role in exploration, is at last destined to take a leading role? The question naturally invites a couple of others: are there experiments that only humans could do on Mars? Could those experiments provide insights profound enough to justify the expense of sending people across interplanetary space? With Mars the scientific stakes are arguably higher than they have ever been. The issue of whether life ever existed on the planet, and whether it persists to this day, has been highlighted by mounting evidence that the Red Planet once had abundant stable, liquid water and by the continuing controversy over suggestions that bacterial fossils rode to Earth on a meteorite (陨石) from Mars. A more conclusive answer about life on Mars, past or present, would give researchers invaluable data about the range of conditions under which a planet can generate the complex chemistry that leads to life. If it could be established that life arose independently on Mars and Earth, the finding would provide the first concrete clues in one of the deepest mysteries in all of science: the prevalence of life in the universe.

Customer: The jeans look cool. May I try them on? Salesman: Sure.______

Speaker A: I"m getting pretty bored. We should do something despite the rain. Speaker B: ______What do you have in mind?

Could the bad old days of economic decline be about to return? Since OPEC agreed to supply-cuts in March, the price of crude oil has jumped to almost $26 a barrel, up from less than $10 last December. This near-tripling of oil prices calls up scary memories of the 1973 oil shock, when prices quadrupled, and 1979—1980, when they also almost tripled. Both previous shocks resulted in double-digit inflation and global economic decline. So where are the headlines warning of gloom and doom this time? The oil price was given another push up this week when Iraq suspended oil exports. Strengthening economic growth, at the same time as winter grips the northern hemisphere, could push the price higher still in the short term. Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past. Rich economics are also less dependent on oil than they were, and so lesssensitive to swings in the oil price. Energy conservation, a shift to other fuels and a decline in the importance of heavy, energy intensive industries have reduced oil consumption. Software, consultancy and mobile telephones use far less oil than steel or car production. For each dollar of GDP(in constant prices) rich economics now use nearly 50% less oil than in 1973. The OECD estimates in itslatest Economic Outlook that, it oil prices averaged $22 a barrel for a full year, compared with $13 in 1998, this would increase the oil import bill in rich economics by only 0.25%～0.50% of GDP. That is less than one-quarter of the income loss in 1974 or 1980. On the other hand, oil-importing emerging economics-to which heavy industry has shifted—have become more energy-intensive, and so could be more seriously squeezed. One more reason not to lose sleep over the rise in oil prices is that, unlike the rises in the 1970s, it has not occurred against the background of general commodity-price inflation and global excess demand. A sizableportion of the world is only just emerging from economic decline. The Economist"s commodity price index is broadly unchanging from a year ago. In 1973 commodity prices jumped by 70%, and in 1979 by almost 30%.

About one million tourists go to Barcelona every year, just to visit the Gaudi"s Church. This unusual church has a strange history. Gaudi was born in Spain in 1852. He had to work and study at the same time. He often missed classes because he had to work, but one day he designed a very unusual showcase for an exhibition in Paris. People began to give him work. He designed houses, offices and gardens. They were all very unusual. He was soon rich and famous. Then a rich bookseller said, "Will you build a church for the poor people of Barcelona? I will pay. I will build schools and workshops, too. They will help the people." "I will do it," said Guadi. He worked for forty years, but he could not finish the church. It was too big. He needed $10, 000, 000. He gave all his money to the church. He was poor again when he died in 1926, and only the front part of the church was finished. Now, architects, engineers and tourists from all over the world like to come and see the church, which is very strange, very modem and very revolutionary.

Senility refers to great losses of intellectual capacity that occurs in old age and is associated with the widespread loss of nerve cells and the shrinkage of brain tissue. Senility is a great decline from a previous intellectual【B1】in an aging person. Memory is the mental capacity most often affected. The memory loss may first show itself clearly in simple absentmindedness or a tendency to forget or【B2】things and repeat oneself in conversation. As the senility progresses, the loss of memory【B3】in scope until the patient can no longer remember basic social and【B4】skills or function independently. There may also be declines in the person"s language skills, spatial or temporal orientation,【B5】or other cognitive capacities and personality changes may also be【B6】to see. Senility usually has a slow, gradual onset and is most common in persons over age 75. The most common cause of the syndrome is Alzheimer"s disease, which【B7】for about 50 percent of all elderly persons with unbalanced mind and is hard to restore a former state. The second most common cause is vascular senility which arises from hypertension (high blood pressure) or some other vascular condition. In this type, a series of small strokes progressively destroy small【B8】of the brain, eventually leading to senility. There is no【B9】for Alzheimer"s disease, but vascular senility can sometimes be prevented or its【B10】slowed by treatment of the underlying systemic vascular disorder. Among other significant causes of senility in the elderly are Huntington"s chorea, Parkinson"s disease, and multiple sclerosis.

IN THE GROUNDS OF A REGENCY MANSION Luxury Self-catering Holiday Cottages in the heart of the Devonshire countryside. Individually styled and color coordinated, these cottages, forming a courtyard round the old thatched pump house, offer elegant and spacious accommodation situated in the beautiful grounds of one of the largest privately owned country estates in the West County. Guests have full use of the owner"s private club. Widworthy Court Sports and Leisure Club"s facilities include tennis court, squash court, heated outdoor swimming pool, pool side restaurant, indoor leisure spa complex comprising swimming pool, Jacuzzi, sun, steam room, solarium and bars. Children and pets welcome ENJOY THE DIFFERENCE Please write or telephone for our full color brochure. The Manager, The Estate Office, Bridwell Park Estate Uffculme, Devon EX15 3BU Telephone (0883) 88814441

Imagine a world in which children would be the rulers and could decide not only the outcome of each and every occurrence, but also dictate the very structure and form of the environment. In this world, a child"s wildest thoughts would become reality, limited only by the extent of his or her imagination. While such a world might sound both fantastic and frightening, at least from a logical, adult perspective, it does exist. What"s more, it has been in existence for some time and is populated by hundreds of thousands of children who spend hours within its boundaries experimenting and learning. This world is not real, at least not in the traditional sense, but exists within a computer and is generated by an educational programming language called LOGO. Unlike other computer languages and programs that are designed to test children and provide applications that formally dispense information, LOGO allows children, even preschool children, to be in total control. Children teach the computer to think and as a result develop and sharpen their own reasoning abilities.

Some psychologists maintain that mental acts such as thinking are not performed in the brain alone, but that one"s muscles also participate. It may be said that we think with our muscles in somewhat the same way that we listen to music with our bodies. You surely are not surprised to be told that you usually listen to music not only with your ears but with your whole body. Few people can listen to music that is more or less familiar without moving their body or more specifically, some part of their body. Often when one listens to a symphonic concert on the radio, he is tempted to direct the orchestra even though he knows there is a competent conductor on the job. Strange as this behavior may be, there is a very good reason for it. One cannot derive all possible enjoyment from music unless he participates, so to speak, in its performance. The listener "feels" himself into the music with more or less noticeable motions of his body. The muscles of the body actually participate in the mental process of thinking "in the same way, but this participation is less obvious because it is less noticeable.

Psychologist George Spilich and colleagues at Washington College in Chestertown, Maryland, decided to find out whether, as many smokers say, smoking helps them to "think and concentrate". Spilich put young non-smokers, active smokers and smokers deprived(被剥夺) of cigarettes through a series of tests. In the first test, each subject(试验对象)sat before a computer screen and pressed a key as soon as he or she recognized a target letter among a grouping of 96. In this simple test, smokers, deprived smokers and nonsmokers performed equally well The next test was more complex, requiring all to scan sequences of 20 identical letters and respond the instant one of the letters transformed into a different one. Non-smokers were faster, but under the stimulation of nicotine(尼古丁), active smokers were faster than deprived smokers. In the third test of short-term memory, non-smokers made the fewest errors, but deprived smokers committed fewer errors than active smokers. The fourth test required people to read a passage, then answer questions about it. Non-smokers remembered 19 percent more of the most important information than active smokers, and deprived smokers bested those who had smoked a cigarette just before testing. Active smokers tended not only to have poorer memories but also had trouble separating important information from insignificant details. "As our tests became more complex", sums up Spilich, "non-smokers performed better than smokers by wider and wider margins". He predicts, "Smokers might perform adequately at many jobs until they got complicated. A smoking airline pilot could fly adequately if no problems arose, but if something went wrong, smoking might damage his mental capacity".

As early as 1637 Ohio made a decision that free, tax supported schools must be established in every town ______ 40 households or more.

In bringing up children, every parent watches eagerly the child"s acquisition(学会) of each new skill the first spoken words, the first independent steps, or the beginning of reading and writing. It is often tempting to hurry the child beyond his natural learning rate, but this can set up dangerous feelings of failure and states of worry in the child. This might happen at any stage. A baby might be forced to use a toilet too early, a young child might be encouraged to learn to read before he knows the meaning of the words he reads. On the other hand, though, if a child is left alone too much, or without any learning opportunities, he loses his natural enthusiasm for life and his desire to find out new things for himself. Parents vary greatly in their degree of strictness towards their children. Some may be especially strict in money matters. Others are severe over times of coming home at night or punctuality for meals. In general, the controls imposed represent the needs of the parents and the values of the community as much as the child"s own happiness. As regards the development of moral standards in the growing child, consistency is very important in parental teaching. To forbid a thing one day and excuse it the next is no foundation for morality(道德). Also, parents should realize that "example is better than precept". If they are not sincere and do not practise what they preach(说教), their children may grow confused, and emotionally insecure when they grow old enough to think for themselves, and realize they have been to some extent fooled. A sudden awareness of a marked difference between their parents" principles and their morals can be a dangerous disappointment.

Within fifteen years Britain and other nations should be well on with the building of huge industrial complexes for the recycling of waste. The word rubbish could lose its meaning because everything that goes into the dumps would be made into something useful. Even the most dangerous and unpleasant wastes would provide energy if nothing else. The latest project is to take a city of around half a million inhabitants and discover exactly what raw materials go into it and what go out. The aim is to find out how much of these raw materials could be provided if a plant for recycling waste were built just outside the city. This plant would recycle not only metal such as steel, lead and copper, but also paper and rubber as well. Another new project is being set up to discover the best ways of sorting and separating the rubbish. When this project is complete, the rubbish will be processed like this: first, it will pass through sharp metal bars which will tear open the plastic bags in which rubbish is usually packed; then it will pass through a powerful fan to separate the lightest elements from the heavy solids; after that grounders and rollers break up everything that can be broken. Finally the rubbish will pass under magnets, which will remove the bits of iron and steel; the rubber and plastic will then be sorted out in the final stage. The first full scale giant recycling plants are, perhaps, fifteen years away. Indeed, with the growing cost of transporting rubbish to more distant dumps, some big cities will-be forced to build their own recycling plants before long.

The bed has been ______ in the family. It was my great grandmother"s original bed.

There is some evidence ______ dishonesty may ebb and flow.

Speaker A: Thank you very much for inviting us to such a delightful dinner. Speaker B: ____

Venus (金星) is known as the earth"s "twin" because the two planets are so like each other in size. The diameter of Venus is about 7, 520 miles (12,100 km. ), smaller than that of the earth. No other planet comes closer to the earth than Venus. At its nearest approach it is about 25,000,000 miles (40,2000,000 km. ) away. As seen from the earth, Venus is the first planet or star that can be seen in the western sky in the evening. At other times, it is the last planet or star that can be seen in the eastern sky in the morning. When Venus is near its brightest point, it can be seen in daylight. Early astronomers called the object that appeared in the evening Hesperus, and Phosphorus in the morning. Later, they realized these two objects were the same planet. They named it Venus in honor of the Roman goddess of love and beauty.

It"s very interesting to note where the debate about diversity(多样化) is taking place. It is taking place primarily in political circles. Here at the College Fund, we have a lot of contact with top corporate(公司的) leaders; none of them is talking about getting rid of those instruments that produce diversity. In fact, they say that if their companies are to compete in the global village and in the global market place, diversity is an imperative. They also say that the need for talented, skilled Americans means we have to expand the pool of potential employees. And in looking at where birth rates are growing and at where the population is shifting, corporate America understands that expanding the pool means promoting policies that help provide skills to more minorities, more women and more immigrants. Corporate leaders know that if that doesn"t occur in our society, they will not have the engineers, the scientists, the lawyers, or the business managers they will need. Likewise, I don"t hear people in the academy saying, "Let"s go backward. Let"s go back to the good old days, when we had a meritocracy(不拘一格选人才)" (which was never true—we never had a meritocracy, although we"ve come closer to it in the last 30 years). I recently visited a great little college in New York where the campus has doubled its minority population in the last six years. I talked with an African American who has been a professor there for a long time, and she remembers that when she first joined the community, there were fewer than a handful of minorities on campus. Now, all of us feel the university is better because of the diversity. So where we hear this debate is primarily in political circles and in the media—not in corporate board rooms or on college campuses.

It is hard to track the blue whale, the ocean"s largest creature, which has almost been killed off by commercial whaling and is now listed as an endangered species. Attaching radio devices to it is difficult, and visual sightings are too unreliable to give real insight into its behavior. So biologists were delighted early this year when with the help of the Navy they were able to track a particular blue whale for 33 days monitoring its sounds. This was possible because of the Navy"s formerly top-secret system of underwater listening devices spanning the oceans. Tracking whales is but one example of an exciting new world just opening to civilian scientists after the cold war as the Navy starts to share and partly uncover its global network of underwater listening system built over the decades to track the ships of potential enemies. Earth scientists announced at a news conference recently that they had used the system for closely monitoring a deep-sea volcanic eruption(爆发) for the first time and that they plan similar studies. Other scientists have proposed to use the network for tracking ocean currents and measuring changes in ocean and global temperatures. The speed of sound in water is roughly one mile a second—slower than through land but faster than through air. What is most important, different layers of ocean water can act as channels for sounds, focusing them in the same way a stethoscope(听诊器) does when it carries faint noises from a patient"s chest to a doctor"s ear. This focusing is the main reason that even relatively weak sounds in the ocean, especially low-frequency ones, can often travel thousands of miles.

Imagine a product that can be used as medicine, a cleaning agent and a beauty treatment. You can eat it, drink its juice, and【C1】______essential oil from it. It is available all over the world, and is inexpensive. You may even have one in your kitchen【C2】______What is it? The lemon! It is thought that lemon【C3】______in Southeast Asia. From【C4】______they were gradually carried westward toward the Mediterranean. Lemon trees thrive in mild【C5】______, which is why they grow so well in places like Italy, Mexico, Spain, and even parts of Africa and Asia. A mature tree, depending on the variety and location, can produce【C6】______from 200 to 1, 500 lemons a year. The cultivated(培育的)varieties【C7】______in different periods, making it possible to harvest lemons all year round. You don"t need lots of space to grow a lemon tree. Even a sunny balcony(阳台)is enough,【C8】______small lemon trees can be grown in pots and can make your house beautiful. They like sunny, wind-free spots where they can soak up the warmth,【C9】______against a wall. However, if the temperature drops a lot during the winter, they need to be【C10】______or brought indoors.