大学英语六级210及答案解析.doc

1、大学英语六级 210及答案解析(总分：427.99，做题时间：132 分钟)一、Part I Writing (3(总题数：1，分数：30.00)1.For this part, you are allowed 30 minutes to write a composition on the topic Fast Food and Traditional Chinese Cuisine. You should write at least 150 words according to the outline given below in Chinese. 1西餐越来越受到中国人的青睐，对你而言

2、，中餐和西餐，更喜欢哪种； 2请给出两条以上的理由支持你的观点； 3对全文作一总结。 （分数：30.00）_二、Part II Reading C(总题数：1，分数：71.00)The Debate over Genetically Modified Foods -Rice with built-in Vitamin A that can help prevent blindness in 100 million children suffering from Vitamin A deficiency -A tomato (hat softens more slowly, allowing i

3、t to develop longer on the vine and keep longer on the shelf -Potatoes that absorb less fat when fried, changing the ever-popular French fries from junk food into a more nutritional food -Strawberry crops that can survive frost These are some of the benefits promised by biotechnology. The debate ove

4、r its benefits and safety, however, continues. Do we really need to fear mutant (突变体) weeds, killer tomatoes, and giant corn and will the benefits be delivered? Conventional Breeding Versus Genetically Modified (GM) Crops For thousands of years farmers have used a process of selection and cross bree

5、ding to continually improve the quality of crops. Even in nature, plants and animals selectively breed, thus ensuring the optimum gene pool for future generations. Traditional breeding methods are slow, requiring intensive labor: While trying to get a desirable trait in a bred species, undesirable t

6、raits will appear and breeders must continue the process over and over again until all the undesirables are bred out. In contrast, organisms acquire one specific gene or a few genes together through genetic modification, without other traits included and within a single generation. However, this tec

7、hnology too is inherently unpredictable and some scientists believe it can produce potentially dangerous results unless better testing methods are developed. Traditional breeding is based on sexual reproduction between, like organisms. The transferred genes are similar to genes in the cell they join

8、. They are conveyed in complete groups and in a fixed sequence that harmonizes with the sequence of genes in the partner cell. In contrast, bioengineers isolate a gene from one type of organism and splice (接合) it haphazardly into the DNA of a dissimilar species, disrupting its natural sequence. Furt

9、her, because the transplanted gene is foreign to its new surroundings, it cannot adequately function without a big artificial boost. One of the main differences between conventional and genetically modified crops is that the former involves crosses either within species or between very closely relat

10、ed species. GM crops can have genes either from closely related species or from distant species, even bacteria and viruses. Benefits: One Side of the Debate -Economical benefits GM supporters tell farmers that they stand to reap enormous profits from growing GM crops. Initially, the cost is expensiv

11、e but money is saved on pesticides. To produce the GM crops, modern biotechnology is used which requires highly skilled people and sophisticated and expensive equipment. Large companies need considerable investments in laboratories, equipment and human resources, hence the reason why GM crops are mo

12、re expensive for farmers than traditional crops. GM crops, farmers are told, are a far better option. It takes a shorter time to produce the desired product. It is precise and there are no unwanted genes. -Herbicide-Resistant Crops So what other advantages do GM crops hold for farmers? GM crops can

13、be produced to be herbicide-resistant. This means that farmers could spray these crops with herbicide and kill the weeds, without affecting the crops. In effect, the amount of herbicide used in one season would be reduced, with a subsequent reduction in costs for farmers and consumers. For Ingard co

14、tton, pest-resistance was built into the cotton, hence reducing and even removing the use of pesticides, which are not only expensive but, more importantly, harmful to the environment. Biotechnology companies are even experimenting with crops that can be genetically modified to be drought- and salt-

15、tolerant, or less reliant on fertilizer, opening up new areas to be farmed and leading to increased productivity. However, the claims of less herbicide usage with GM crops have till now not been independently supported by facts. -Better Quality Foods Even animals can be genetically modified to be le

16、aner, grow faster, and consume less food. They could be modified to have special characteristics, such as greater milk production in cows. These modifications again lead to improved productivity for farmers and ultimately lower costs for the consumer. Modified crops could perhaps prevent outbreaks s

17、uch as foot and mouth disease, which has devastated many farmers and local economies. No such products have been released to date; however, some are under consideration for release. For example, GM salmon, capable of growing almost 30 times faster than natural salmon, may soon be approved by the FDA

18、 (Food and Drug Administration) in the U.S. for release into open waters without a single study on the impact on human health or the environment. Risks: the Other Side of the Debate The major concerns of those who oppose GM foods center on the following: -Environmental Damage The problem with GM cro

19、ps is that there is little known about what effect they will have in, say, 20 years time. The genetic structure of any living organism is complex and GM crop tests focus on short-term effects. Not all the effects of introducing a foreign gene into the intricate genetic structure of an organism are t

20、ested. Will the pests that a crop was created to resist eventually become resistant to this crop? Then there is always the possibility that we may not be able to destroy GM crops once they spread into the environment. -Risk to Food Web A further complication is that the pesticide produced in the cro

21、p may unintentionally harm creatures. GM crops may also pose a health risk to native animals that eat them. The animals may be poisoned by the built-in pesticides. Tests in the U.S. showed that 44% of caterpillars of the monarch butterfly died when fed large amounts of pollen (花粉) from GM corn. -Cro

22、ss-Pollination(授粉) Cross-pollination is a concern for both GM crops and conventional breeding, especially with the more serious weeds that are closely related to the crops. With careful management this may be avoided. Genetic modification to herbicide-resistant crops could insert the gene that preve

23、nts the problem. The number of herbicide-tolerant weeds has increased over the years from a single report in 1978 to the 188 herbicide-tolerant weed types in 42 countries reported in 1997. They are an ever-increasing problem and genetic engineering promises to stop it. But will genes from GM plants

24、spread to other plants, creating superweeds and superbugs we wont be able to control? -GM Mix-Ups Humans can inadvertently eat foods that contain GM products meant as animal feed, i.e., crops modified for increased productivity in animals. This happened in the U.S., where traces of a StarLink GM cro

25、p, restricted to use only in feed, were found in taco shells. Apparently no one became ill, but other such occurrences may lead to health problems. -Disease Another concern is disease. Since some crops are modified using the DNA from viruses and bacteria, will we see new diseases emerge? What about

26、the GM crops that have antibiotic-resistant marker genes? Marker genes are used by scientists to determine whether their genetic modification of a plant was successful. Will these antibiotic-resistant genes be transferred to microorganisms that cause disease? We already have a problem with ineffecti

27、ve antibiotics. How can we develop new drugs to fight these new bugs? Conclusion Proponents of GM crops claim that advantages may be many, such as: -improved storage and nutritional quality -pest- and disease-resistance -selective herbicide-tolerance -tolerance of water, temperature and saline extre

28、mes -improved animal welfare -higher yields and quality However, until further studies can show that GM foods and crops do not pose serious threats to human health or the worlds ecosystems, the debate over their release will continue. Living organisms are complex and tampering with their genes may h

29、ave unintended effects. It is in our common interest to support scientists and organizations concerned, such as Friends of the Earth who demand “mandatory labeling of these food products, independent testing for safety and environmental impacts, and liability for harm to be assumed by biotech compan

30、ies“. （分数：71.00）(1).Conventional breeding is a slow, predictable process.（分数：7.10）A.YB.NC.NG(2).Even genes from animals can be used to engineer crops.（分数：7.10）A.YB.NC.NG(3).Safety studies have been done on GM salmon.（分数：7.10）A.YB.NC.NG(4).This article tells us that further studies are needed to asse

31、ss the potential risks of GM foods even though the technology promises many benefits.（分数：7.10）A.YB.NC.NG(5). 1is inherently dangerous unless better testing methods are developed.（分数：7.10）填空项 1:_(6).Growing GM crops is initially 1 but cheaper in the long run.（分数：7.10）填空项 1:_(7).GM fields use 1 herbic

32、ides.（分数：7.10）填空项 1:_(8).No one knows exactly how GM crops will affect the environment because genetic structure is complex and the related tests now mainly study 1.（分数：7.10）填空项 1:_(9).The native animals that eat GM crops might be poisoned by 1.（分数：7.10）填空项 1:_(10).Scientists use 1 to test whether t

33、heir genetic modification of a plant is successful.（分数：7.10）填空项 1:_三、Listening Comprehens(总题数：1，分数：15.00)A.He will tell Mary how to operate the dishwasher.B.He will wash the dishes himself instead.C.He will help Bill to translate the manual.D.He himself will operate the dishwasher.A.Lose weight.B.Qu

34、it smoking.C.Weight himself frequently.D.Have a talk with the doctor.A.The woman should have complained to her neighbor.B.The woman should stay out until the neighbors are quiet.C.The woman should have stayed at the library.D.The lab will be a better place for reading.A.Check the figures later today

35、.B.Do the calculations again tomorrow.C.Bring a calculator tomorrow.D.Calculate the number fight now.A.She doesnt remember much about the city.B.Shes never been to the city.C.She would find someone else to help.D.She would talk to the man later.A.She thinks the man should have helped earlier.B.She d

36、oesnt need the mans help.C.She doesnt know the boxes are heavy.D.She wants the man to help with the boxes.A.She let the man use her books for the weekend.B.She brought the books the man asked for.C.She borrowed the books from the man.D.She offered to help the man.A.Shed like to have the windows open

37、.B.She likes to have the air conditioner on.C.The air is heavily polluted.D.The windows are already open.A.Hes going to visit a photo studio.B.Hes just had his picture taken.C.Hes on the way to the theater.D.Hes just returned from a job interview.A.At a gas station.B.In a park.C.In an emergency room

38、.D.At a garage.四、Section A(总题数：2，分数：10.00)A.The mans last appointment.B.Professor Irwins office hours.C.Student advisement during registration.D.The mans health problems.A.Tuesday at two oclock.B.This afternoon at three oclock.C.Thursday at two oclock.D.Now.A.He should have made an appointment.B.He

39、should have called to cancel his appointment.C.He should have come for his appointment.D.He should have stayed at home until he was well.A.He has a lot of expenses including student loans.B.Hes in debt and is trying to borrow money.C.He has a decent job, but hes looking for a new one.D.He lent money

40、 for his friends and give financial advices.A.A small place with a nice view of the city.B.A spacious apartment that includes cable TV.C.An apartment downtown with free parking.D.A small place with utilities and cable TV.A.He tries to go out to eat every night.B.He spends around $ 400 a month.C.He d

41、oesnt know how to cook very well.D.He prefers to eat alone.A.He should be careful when using his credit cards.B.He should cook by himself.C.He should stop spending money on entertainment.D.He ought to get rid of his car to save money.五、Section B(总题数：3，分数：10.00)A.Only breakfast.B.Only lunch.C.Only ni

42、ght-meals.D.All of the above.A.Two ways.B.Three ways.C.Four ways.D.Five ways.A.Diners existed before fast-food restaurants.B.The menu included more food than sandwiched and coffee.C.Burger King is a fast-food restaurant.D.Sandwiches became bigger.A.They thought it quite acceptable.B.They believed it

43、 to be a luxury.C.They took it to be a trend.D.They considered it avoidable.A.Critical.B.Skeptical.C.Serious.D.Casual.A.When people consider marriage an important part of their lives.B.When the costs of getting a divorce become unaffordable.C.When the current marriage law is modified.D.When husband

44、and wife understand each other better.A.His father caught a serious disease.B.His mother passed away.C.His mother left him to marry a rich businessman.D.His father took to drinking.A.He disliked being disciplined.B.He was expelled by the university.C.He couldnt pay his gambling debts.D.He enjoyed wo

45、rking for a magazine.A.His poems are heavily influenced by French writers.B.His stories are mainly set in the State of Virginia.C.His work is difficult to read.D.His language is not refined.A.He grieved to death over the loss of his wife.B.He committed suicide for unknown reasons.C.He was shot dead

46、at the age of 40.D.He died of heavy drinking.六、Section C(总题数：1，分数：10.00)President Clinton later today joins (36) 1 presidents Ford, Carter and Bush at “the presidents summit for Americas future “(37) 2 at recruiting one million volunteer tutors to provide afterschool, weekend and summer reading help

47、 for up to three million children. Mr. Clinton will ask Congress this coming week for nearly three (38) 3dollars to fund a five-year program called “America Reads “. The program would fund the (39) 4 efforts of 20 thousand reading (40) 5; and it would also give (41) 6to help parents help children re

48、ad by the third grade, or about age eight. During his Saturday radio (42) 7, the president explained why the program is important. “We need America Reads and we need it now. Studies show that if the (43) 8fourth-graders fail to read well, (44) 9. But, 40 percent of them still cant read at a basic level. “ Volunteer tutors, who provide community service in exchange for college funding, are being used in Literacy and tutoring programs (45) 10. The president says many of the Philadelphia summits corporate sponsors will recruit tutors. (46) 11. （分数：10.00）填空项 1:_填空项 1:_填空项 1:_填空项