[外语类试卷]大学英语六级模拟试卷519及答案与解析.doc

1、大学英语六级模拟试卷 519及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write a short essay entitled Cheating on Exams. You should write at least 150 words following the outline given below. 1在各类考试中，总发现有学生作弊的现象 2作弊所带来的 不良影响 3怎样制止作弊 Cheating on Exams 二、 Part II Reading Comp

2、rehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-4, mark： Y (for YES) if the statement agrees with the information given in the passage; N (for NO) if the

3、 statement contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 1 Genetically Modified Foods Feed the World? If you want to spark a heated debate at a dinner party, bring up the topic about genetically modified foods. For many people, t

4、he concept of genetically altered, high-tech crop production raises all kinds of environmental, health, safety and ethical questions. Particularly in countries with long agrarian (农业的 ) traditions and vocal green lobbies the idea seems against nature. In fact, genetically modified foods are already

5、very much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the U.S. last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the U.S. this year. The

6、 genetic genie is out of the bottle. Yet there are clearly some very real issues that need to be resolved. Like any new product entering the food chain, genetically modified foods must be subjected to rigorous testing. In wealthy countries, the debate about biotech is tempered by the fact that we ha

7、ve a rich array of foods to choose from and a supply that far exceeds our needs. In developing countries desperate to feed fast-growing and underfed populations, the issue is simpler and much more urgent: Do the benefits of biotech outweigh the risks? The statistics on population growth and hunger a

8、re disturbing. Last year the worlds population reached 6 billion. And by 2050, the UN estimates, it will be probably near 9 billion. Almost all that growth will occur in developing countries. At the same time, the worlds available cultivable land per person is declining. Arable land has declined ste

9、adily since 1960 and will decrease by half over the next 50 years, according to the International Service for the Acquisition of Agri-Biotech Applications (ISAAA). How can biotech help? Biotechnologists have developed genetically modified rice that is fortified with beta-carotene (胡萝卜 素 ) which the

10、body converts into vitamin A and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where food shortages are caused by crop damage attributable to pests, drought, poor soil and crop viruses, bacteria or fungi.

11、 Damage caused by pests is incredible. The European corn borer (螟虫 ) for example, destroys 40 million tons of the worlds corn crops annually, about 7% of the total. Incorporating pest-resistant genes into seeds can help restore the balance. In trials of pest-resistant cotton in Africa, yields have i

12、ncreased significantly. So far, fears that genetically modified, pest-resistant crops might kill good insects as well as bad appear unfounded. Viruses often cause massive failure in staple crops in developing countries. Two years ago, Africa lost more than half its cassava (木薯 ) crop a key source of

13、 calories to the mosaic virus. Genetically modified, virus-resistant crops can reduce that damage, as can drought-tolerant seeds in regions where water shortages limit the amount of land under cultivation. Biotech can also help solve the problem of soil that contains excess aluminum, which can damag

14、e roots and cause many staple-crop failures. A gene that helps neutralize aluminum toxicity (毒性 ) in rice has been identified. Many scientists believe biotech could raise overall crop productivity in developing countries as much as 25% and help prevent the loss of those crops before they are harvest

15、ed. Yet for all that promise, biotech is far from being the whole answer. In developing countries, lost crops are only one cause of hunger. Poverty plays the largest role. Today more than 1 billion people around the globe live on less than 1 dollar a day. Making genetically modified crops available

16、will not reduce hunger if farmers cannot afford to grow them or if the local population cannot afford to buy the food those farmers produce. Biotech has its own “distribution“ problems. Private-sector biotech companies in the rich countries carry out much of the leading-edge research on genetically

17、modified crops. Their products are often too costly for poor farmers in the developing world, and many of those products wont even reach the regions where they are most needed. Biotech firms have a strong financial incentive to target rich markets first in order to help them rapidly recoup the high

18、costs of product development. But some of these companies are responding to needs of poor countries. More and more biotech research is being carried out in developing countries. But to increase the impact of genetic research on the food production of those countries, there is a need for better colla

19、boration between government agencies both local and in developed countries and private biotech firms. The ISAAA, for example, is successfully partnering with the U.S. Agency for International Development, local researches and private biotech companies to find and deliver biotech solutions for farmer

20、s in developing countries. Will “Franken-foods“ feed the world? Biotech is not a panacea (治百病的药 ), but it does promise to transform agriculture in many developing countries. If that promise is not fulfilled, the real losers will be their people, who could suffer for years to come. The world seems in

21、creasingly to have been divided into those who favor genetically modified (GM) foods and those who fear them. Advocates assert that growing genetically altered crops can be kinder to the environment and that eating foods from those plants is perfectly safe. And, they say, genetic engineering which c

22、an induce plants to grow in poor soils or to produce more nutritious foods will soon become an essential tool for helping to feed the worlds burgeoning (迅速发展的 ) population. Skeptics contend that genetically modified crops could pose unique risks to the environment and to health risks too troubling t

23、o accept placidly. Taking that view, many European countries are restricting the planting and importation of genetically modified agricultural products. Much of the debate hinges on perceptions of safety. But what exactly does recent scientific research say about the hazards? Two years ago in Edinbu

24、rgh, Scotland, eco-vandals stormed a field, crushing canola plants. Last year in Maine, midnight raiders hacked down more than 3,000 experimental poplar trees. And in San Diego, protesters smashed sorghum and sprayed paint over greenhouse walls. This far-flung outrage took aim at genetically modifie

25、d crops. But the protests backfired: all the destroyed plants were conventionally bred. In each case, activists mistook ordinary plants for genetically modified varieties. Its easy to understand why. In a way, genetically modified crops now on some 109 million acres of farmland worldwide are invisib

26、le. You cant see, taste or touch a gene inserted into a plant or sense its effects on the environment. You cant tell, just by looking, whether pollen containing a foreign gene can poison butterflies or fertilize plants miles away. That invisibility is precisely what worries people. How, exactly, wil

27、l genetically modified crops affect the environment and when will we notice? Advocates of genetically modified or transgenic crops say the plants will benefit the environment by requiring fewer toxic pesticides than conventional crops. But critics fear the potential risks and wonder how big the bene

28、fits really are. “We have so many questions about these plants,“ remarks Guenther Stotzky, a soil microbiologist at New York University. “Theres a lot we dont know and need to find out.“ As genetically modified crops multiply in the landscape, unprecedented numbers of researchers have started fannin

29、g into the fields to get the missing information. Some of their recent findings are reassuring; others suggest a need for vigilance. 2 How much corn planted in the U.S. last year was genetically modified? （ A） More than half. （ B） 65 million acres. （ C） One third. （ D） Three quarters. 3 Why is the d

30、ebate on genetically modified foods more heated in developing countries? （ A） They have a rich range of foods. （ B） They like traditional and natural food. （ C） They have to feed fast-growing populations. （ D） The risks of GM food outweigh the benefits. 4 Biotech can improve productivity, which can

31、be proved by trials of_. （ A） pest-resistant cotton in Africa （ B） the European corn borer （ C） the genetically modified rice （ D） vitamin A much more converted 5 What have scientists done to solve the problem of soil that contains excess aluminum? （ A） They have engineered the crops to be virus-res

32、istant. （ B） They have found a gene to fight the excess toxicity. （ C） They have modified the crops to be drought-tolerant. （ D） They have improved the soil by absorbing excess aluminum. 6 The most important factor that leads to hunger in developing countries is_. （ A） lost crops （ B） global greenho

33、use effect （ C） economic crisis （ D） poverty 7 Biotech firms have not much interest in the developing world market because_. （ A） running business there needs much in distribution （ B） farmers there are too poor to buy their products （ C） these firms want to keep their technology secret （ D） farmers

34、 there dont like genetically modified crops 8 Advocates of transgenic crops claim that_. （ A） these crops have no harm to the environment in their growing （ B） food from these crops are healthier than from the conventional （ C） these crops will certainly replace the conventional （ D） these crops can

35、 greatly help to feed the world 9 Eco-vandals in Edinburgh stormed a field two years ago, aiming at_. 10 Raiders missed the genetically modified varieties because of the_of such plants. 11 Guenther Stotzky is afraid of the transgenic crops because of_. Section A Directions: In this section, you will

36、 hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choice

37、s marked A, B, C and D, and decide which is the best answer. （ A） She should not buy a coffee maker at all. （ B） She will buy another coffee maker some day. （ C） The quality of the coffee maker she bought was poor. （ D） She will complain to the shop manager about the coffee maker. （ A） The man has a

38、n internal injury. （ B） The man should buy a new bike. （ C） The man should go to see a doctor. （ D） The man has nothing wrong with his back. （ A） Its a shame to scold the fans behaviors. （ B） Fans are mad and should be scolded severely. （ C） The fans are solely responsible for their behaviors. （ D）

39、We shouldnt only blame the fans for their behaviors. （ A） The manual is of no use. （ B） There are some parts missing. （ C） He cant understand the manual. （ D） An hour is not enough to read the manual. （ A） He wants to have another cup of tea. （ B） He has had enough tea for the moment. （ C） He wants

40、the woman to buy the tea for him. （ D） He will buy some tea from China by himself. （ A） It is very popular. （ B） It will be launched this Wednesday. （ C） Its not sold at the campus bookstore. （ D） It ran a second print three weeks ago. （ A） The weather does not permit. （ B） There isnt a shortcut to

41、the peak. （ C） Theyve got enough mushrooms to cook at home. （ D） They cant get home before dark if they go on climbing. （ A） Stay up and go for the meeting. （ B） Stay at the apartment and sleep for a while. （ C） Catch up with the woman after he wakes up. （ D） Go with the woman for fear of oversleepi

42、ng. （ A） Confident. （ B） Hesitant. （ C） Determined. （ D） Doubtful. （ A） An export salesman working overseas. （ B） A trainee working through every branch. （ C） A production manager in a branch. （ D） A policy-maker in the company. （ A） Trainees are required to sign contracts initially. （ B） Trainees p

43、erformance is evaluated occasionally. （ C） Trainees starting salary is 870 pounds. （ D） Trainees cannot quit the management scheme at will. （ A） New foods to try when traveling. （ B） Making reservations for the best travel. （ C） Avoiding gaining weight while traveling. （ D） Adjusting to time changes

44、 when traveling. （ A） It changes the bodys metabolism through rapid weight gain. （ B） It tricks the body into responding as if it were in a different time zone. （ C） It promotes increased alertness by adding snacks to the diet. （ D） It builds resistance to illness by increasing intake of vitamins. （

45、 A） He feels rushed. （ B） He hates to pack. （ C） He doesnt like to restrict his diet. （ D） Hes worried about his lecture. （ A） He has a big appetite. （ B） He eats only at regular mealtimes. （ C） He avoids new foods. （ D） He eats only healthful foods. Section B Directions: In this section, you will h

46、ear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） How to handle spiders. （ B） Spiders in the United S

47、tates. （ C） Peoples fear of spiders. （ D） A special kind of spider. （ A） Most spiders will not bite even when handled. （ B） Most spiders are poisonous and dangerous. （ C） Most spiders are likely to attack people. （ D） Most spiders have sharp eyes. （ A） She cannot find a husband for herself. （ B） The

48、 female spider is larger than the male one. （ C） The female spider often eats her husband. （ D） She is a black female spider. （ A） Competition in business. （ B） Government grants. （ C） A type of economic policy. （ D） International transportation practices. （ A） American industrialists. （ B） French e

49、conomists. （ C） International leaders. （ D） Civil War veterans. （ A） The rights of private business owners should be protected. （ B） The government shouldnt interfere in private business. （ C） Politicians should support industrial growth. （ D） Competition among companies should be restricted. （ A） It is the same as self-respect. （ B） It is totally different from self-respect. （ C） It is to evaluate positively and hold high regard. （ D） It is to think only the positi