清华大学2003年考博英语真题及答案解析

2015-01-09 11:03:34来源：网络

　　Part Ⅲ Reading Comprehension (40%)

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　　Directions: There are 4 reading passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice and then mark the corresponding letter on the Answer Sheet.

　　Questions 36 to 40 are based on the following passage:

　　A scorching sun, an endless sea of sand and a waterless, forbiddingly lonely land—that is the image most people have of deserts. But how true is this picture? Deserts are drylands where rainfall is low. This is not to say rain never falls in deserts: it may fall once or twice a year in a fierce torrent that fades almost as soon as it has begun, or which evaporates in the hot air long before it has got anywhere near the earth. It may fall in a sudden sweeping flood that carries everything in its path. Rains may only come once in five or six years or not fall for a decade or more. The Mojave desert in the United States remained dry for twenty-five years.

　　Without water no living thing can survive, and one feature of the true desert landscape is the absence of vegetation. With little rain and hardly any vegetation the land suffers under the sun. There are virtually no clouds or trees to protect the earth's surface and it can be burning hot. Under the sun, soils break up and crack. Wind and torrential rain sweep away and erode the surface further. Eight million square kilometers of the world's land surface is desert. Throughout history deserts have been expanding and retreating again. Cave paintings show that parts of the Sahara Desert were green and fertile about 10,000 years ago, and even animals like elephants and giraffes roamed the land. Fossil and dunes found in fertile and damp parts of the world show that these areas were once deserts. But now the creation of new desert areas is happening on a colossal scale. Twenty million square kilometers, an area twice the size of Canada, is at a high to very high risk of becoming desert. With a further 1.25 million square kilometers under moderate risk, an area covering 30% of the earth's land surface is desert, becoming desert, or in danger of becoming desert. The rate of growth of deserts is alarming. The world's drylands which are under threat include some of the most important stock-rearing and wheat-growing areas and are the homes of 600—700 million people. These regions are becoming deserts at the rate of more than 58, 000 square kilometers a year or 44 hectares a minute. In North Africa at least 100, 000 hectares of cropland are lost each year. At this rate there is a high risk that we will be confined to living on only 50% of this planet's land surface within one more century unless we are able to do something about it.

　　36. What does the passage tell us about rainfall in the desert?

　　A. It never rains.

　　B. It rains to little that nothing can live.

　　C. It rains unexpectedly.

　　D. It rains very infrequently.

　　37. Desert soils break up and crack because of__________.

　　A. the effects of wind and rain.

　　B. the lack of protection from the sun.

　　C. the tropical location of deserts.

　　D. the absence of rain.

　　38. What do we learn about deserts from this text?

　　A. Deserts can change into green and fertile areas.

　　B. Certain areas have always been desert.

　　C. Deserts were once the home of elephants and giraffes.

　　D. Deserts have been growing since the beginning of the world.

　　39. How much of the world's land surface is at risk of becoming desert?

　　A. Less than ten million square kilometers.

　　B. Twenty million square kilometers.

　　C. More than twenty million square kilometers.

　　D. 30% of the world's land surface.

　　40. What does the writer think about the creation of new desert areas?

　　A. It is a natural development.B. The problem is not very serious.

　　C. It is a very worrying problem. D. The situation will improve in time.

　　Questions 41 to 45 are based on the following passage:

　　The first thing to notice is that the media we're all familiar with----from books to television----are one-way propositions: they push their content at us. The Web is two-way, push and pull. In finer point, it combines the one-way reach of broadcast with the two-way reciprocity (互惠)of a mid-cast. Indeed, its user can at once be a receiver and sender of broadcast----a confusing property, but mind-stretching!

　　A second aspect of the Web is that it is the first medium that honors the notion of multiple intelligences. This past century's concept of literacy grew out of our intense belief in text, a focus enhanced by the power of one particular technology-the typewriter. It became a great tool for writers but a terrible one for other creative activities such as sketching, painting, notating music, or even mathematics. The type -writer prized one particular kind of intelligence, but with the Web, we suddenly have a medium that honors multiple forms of intelligence—abstract, textual, visual, musical, social, and kinesthetic. As educators, we now have a chance to construct a medium that enables all young people to become engaged in their ideal way of learning. The Web affords the match we need between a medium and how a particular person learns.

　　A third and unusual aspect of the Web is that it leverages (起杠杆作用)the small efforts of the many with the large efforts of the few. For example, researchers in the Maricopa County Community College system in Phoenix have found a way to link a set of senior citizens with pupils in the Longview Elementary School, as helper-mentors(顾问). It's wonderful to see-kids listen to these grandparents better than they do to their own parents, the mentoring really helps their teachers, and the seniors create a sense of meaning for themselves. Thus, the small efforts of the man—the seniors—complement the large efforts of the few—the teachers. The same thing can be found in operation at Hewlett-Packard, where engineers use the Web to help kids with science or math problems. Both of these examples barely scratch the surface as we think about what's possible when we start interlacing resources with needs across a whole region.

　　41. What does the word mind-stretching imply?

　　A. Obtaining one's mental power.

　　B. Strengthening one's power of thought.

　　C. Making great demands on one's mental power.

　　D. Exerting one's mental power as far as possible.

　　42. What is a terrible tool for activities such as sketching and painting?

　　A. Technology B. Typewriter

　　C. Text D. The web

　　43. Which group of people make some efforts to help pupils in elementary schools?

　　A. Teachers B. Researchers

　　C. Grandparents D. Senior citizens

　　44. The sentence the seniors create a sense of meaning for themselves means the seniors__________.

　　A. acquire a new meaning of their lives

　　B. understand the meaning of the web

　　C. create a web site for themselves

　　D. add a new meaning to the web

　　45. The expression “scratch the surface” most probably means__________.

　　A. think hard in a puzzled way

　　B. deal with a problem thoroughly

　　C. treat a subject without being thorough

　　D. work out a solution for a problem easily

　　Questions 46 to 50 are based on the following passage:

　　There is no question that the old style of air pollution could kill people. In one week following the infamous “peasouper” fog in December 1952, 4, 700 people died in London. Most of these people were elderly and already had heart or lung diseases. A sereis of these killer fogs eventually led to the British Passing the Clean Air Act which restricted the burning of coal.

　　Fortunately the effect of smog on the lungs is not so dramatic. Scientists have now conducted a number of laboratory experiments in which volunteers are exposed to ozone inside a steel chamber for a few hours. Even at quite low concentrations there is a reversible fall in lung function, an increase in the irritability of the lungs and evidence of airway inflammation(发炎). Although irritable and inflamed lungs are particularly seen in people with asthma(哮喘)and other lung diseases, these effects of ozone also occur in healthy subjects. Similar changes are also seen after exposure to nitrogen dioxide, although there is some disagreement about the concentration at which they occur.

　　Other studies have found that people living in areas with high levels of pollution have more symptoms and worse lung function than those living in areas with clean air. Groups of children attending school camps show falls in lung function even at quite low concentrations of ozone. There is also a relationship between ozone levels and hospital admissions for asthma, both in North America and Australia. It is suspected that long-term exposure to smog may result in chronic bronchitis(支气管炎)and emphysema(肺气肿), but this has yet to be proven.

　　Recently an association has been found between the levels of particles in the air and death rates in North American cities. The reason for this association is not understood and as yet there is no evidence this occurs in Australia. However, we do know that hazy days are associated with more asthma attacks in children.

　　46. Which of the following is NOT the result of laboratory experiments?

　　A. Low concentrations

　　B. Fall in lung function

　　C. Irritability of the lungs

　　D. Air way inflammation

　　47. Irritable and inflamed lungs are also seen in people with__________.

　　A. asthma B. lung diseases

　　C. good health D. weak health

　　48. Which of the following is NOT mentioned as a possible cause of lung diseases?

　　A. The burning of coal B. Long-term exposure to smog

　　C. Exposure to nitrogen dioxide D. Attending school camps

　　49. The relationship between exposure to__________has not yet been determined.