大学英语考试复习资料大学六级模拟238Word文件下载.docx

1、问题:1.1上图为市市民对中学生出国留学看法的统计，请简单描述该图 2请说明两种观点可能的论述理由 3你对出国留学的看法，并为人们的顾虑提供可能的解决方法 答案:Should High School Students Study Abroad? In this global village, more and more, Chinese are studying abroad, and the age of overseas students is falling. As to whether high school students should join the trend, people

2、 have split views. According to a study in X city, 65% of the people go in for it, while 35% are opposed to it. The proponents believe studying abroad is a good thing, if circumstances allowed. First, going abroad offers a foreign language environment. Also students may experience another education

3、system and life style. Moreover, high school students can foster a sense of independence, in order to better prepare for the future. However, some people still hold reservation. One of the concerns is the high tuition fee and living costs. Another is that some students may abuse freedom due to lack

4、of-discipline. Personally, I am supportive of such a choice for young people like high school students. They can not only learn advanced technologies, but also gain an insight into other cultures. As for the big costs, students may apply for scholarships or do some part-time jobs. What is more, stud

5、ying abroad and parental supervision are not mutually exclusive. Thanks to modern communication facilities, parents may offer constant encouragement and guidance from a distance.写作提示：图表题在六级考试中并不常见，但是2002年也出现过，因此最好也要有一定的了解。根据提纲，对图表的描述仅占全文三分之一左右的内容，因此重点其实还是考生熟悉的议论文体。对于该题，第一段按照要求列出持两种观点人的比例，可以自己设计一个调查。

6、第二段提出双方的一些主要理由，例如开拓视野、培养自主能力、费用高昂、背井离乡等等。第三段可以做一个总结，并针对前文提到的反方观点给予解决方法。 Part Reading Comprehension （Skimming and Scanning） In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-4, mark Y （for YES） if the statement agrees wit

7、h the information given in the passage; N （for NO） if the statement contradicts the information given in the passage; NG （for NOT GIVEN） if the information is not given in the passage. For questions 5-10, complete the sentences with the information given in the passage. The Debate over Genetically M

8、odified Foods Rice with built-in Vitamin A that can help prevent blindness in 100 million children suffering from Vitamin A deficiency A tomato that softens more slowly, allowing it to develop longer on the vine and keep longer on the shelf Potatoes that absorb less fat when fried, changing the ever

9、-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 over its benefits and safety, however, continues. Do we really need to fear mutant （突变体） weeds, killer tomatoes, and giant co

10、m 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 breeding to continually improve the quality of crops. Even in nature, plants and animals selectively breed, thus ensuring the op

11、timum 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 traits will appear and breeders must continue the process over and over again until all the undesirables are bred out. In con

12、trast, organisms acquire one specific gene or a few genes together through genetic modification, without other traits included and within a single generation. However, this technology too is inherently unpredictable and some scientists believe it can produce potentially dangerous results unless bett

13、er 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. They are conveyed in complete groups and in a fixed sequence that harmonizes with the sequence of genes in the partner cel

14、l. 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. Further, because the transplanted gene is foreign to its new surroundings, -it cannot adequately function without a big artifici

15、al 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 related species. GM crops can have genes either from closely related species or from distant species, even bacteria and viruses.

16、 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 expensive but money is saved on pesticides. To produce the GM crops, modern biotechnology is used which requires highly skilled peop

17、le and sophisticated and expensive equipment. Large companies need considerable investments in laboratories, equipment and human resources, hence the reason why GM crops are more expensive for farmers than traditional crops. GM crops, farmers are told, are a far better option. It takes a shorter tim

18、e 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 be produced to be herbicide-resistant. This means that farmers could spray these crops with herbicide and kill the weeds, wit

19、hout 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 cotton, pest-resistance was built into the cotton, hence reducing and even removing the use of pesticides, which are not only e

20、xpensive but, more importantly, harmful to the environment. Biotechnology companies are even experimenting with crops that can be genetically modified to be drought- and salt-tolerant, or less reliant on fertilizer, opening up new areas to be farmed and leading to increased productivity. However, th

21、e 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 leaner, grow faster, and consume less food. They could be modified to have special characteristics, such as greater milk product

22、ion in cows. These modifications again lead to improved productivity for farmers and ultimately lower costs for the consumer. Modified crops could perhaps prevent outbreaks such as foot and mouth disease, which has devastated many farmers and local economies. No such products have been released to d

23、ate; 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 （Food and Drug Administration） in the U.S. for release into open waters without a single study on the impact on human health o

24、r 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 crops is that there is little known about what effect they will have in, say, 20 years time. The genetic structure of any living org

25、anism 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 tested. Will the pests that a crop was created to resist eventually become resistant to this crop? Then there is always the possib

26、ility 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 crop may unintentionally harm creatures. GM crops may also pose a health risk to native animals that eat them. The animals may be poi

27、soned 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. Cross-Pollination （授粉） Cross-pollination is a concern for both GM crops and conventional breeding, especially with the more serious we

28、eds 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 prevents the problem. The number of herbicide-tolerant weeds has increased over the years from a single report in 1978 to the 188 herbi

29、cide-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 spread to other plants, creating superweeds and superbugs we wont be able to control?GM Mix-Ups Humans can inadvertently eat foods

30、 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 crop, restricted to use only in feed, were found in taco shells. Apparently no one became iii, but other such occurrences may lead to h

31、ealth 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 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 ineffective antibiotics. How can we develop new drugs to figh