1、大学英语四级综合-26 及答案解析(总分：180.00，做题时间：90 分钟)一、Unit 3(总题数：4，分数：180.00)Passage OneExperiments under way in several labs aim to create beneficial types of genetically modified (GM) foods, including starchier potatoes and caffeine-free coffee beans. Genetic engineers are even trying to transfer genes from a
2、cold-winter fish to make a frost-resistant tomato.A low-sugar GM strawberry now in the works might one day allow people with health problems such as diabetes to enjoy the little delicious red fruits again. GM beans and grains supercharged with protein might help people at risk of developing kwashior
3、kor. Kwashiorkor, a disease caused by severe lack of protein, is common in parts of the world where there are severe food shortages.Commenting on GM foods, Jonathon Jones, a British researcher, said: “The future benefits will be enormous, and the best is yet to come.“To some people, GM foods are no
4、different from unmodified foods. “A tomato is a tomato,“ said Brian Sansoni, an American food manufacturer.Critics of GM foods challenge Sansonis opinion. They worry about the harm that GM crops might do to people, other animals, and plants.In a recent lab study conducted at Comell University, scien
5、tists tested pollen made by Bt corn, which makes up one-fourth of the U.S. com crop. The scientist sprinkled the pollen onto milkweed, a plant that makes a milky juice and is the only known food source of the monarch butterfly caterpillar. Within four days of munching on the milkweed leaves, ahnost
6、half of a test group of caterpillars had died. “Monarchs are considered to be a flagship species for conservation,“ said Comell researcher Linda Raynor. “This is a warning bell.“Some insects that are not killed by GM foods might find themselves made stronger. How so? The insecticides used to protect
7、 most of todays crops are sprayed on the crops when needed and decay quickly in the environment. But GM plants produce a continuous level of insecticide. Insect species feeding on those crops may develop resistance to the plants and could do so in a hurry, say the critics. Insects may also develop a
8、 resistance to the insecticide Bt.At the forum on GM food held last year in Canada, GM crops that have been made resistant to the herbicide might crossbreed with wild plants, creating “super weeds“ that could take over whole fields.So where do you stand? Should GM food be banned in the United States
9、, as they are in parts of Europe? Or do their benefits outweigh any of the risks they might carry?（分数：45.00）(1).Paragraphs one, two and three try to give the idea that _（分数：9.00）A.GM foods may bring about great benefits to humansB.we cannot recognize the benefits of GM foods too earlyC.GM foods may
10、have both benefits and harmD.GM foods are particularly good to the kwashiorkor patients(2).Why is the case of the pollen-sprayed milkweed cited in Paragraph six?（分数：9.00）A.It is cited to show GM foods can kill insects effectively.B.It is cited to show GM foods contain more protein.C.It is cited to s
11、how GM foods also have a dark side.D.It is cited to show GM foods may harm crops.(3).What happens to those insects when not killed by the spray of insecticide?（分数：9.00）A.They may lose their ability to produce offspring.B.They may have a higher ability to adapt to the environment.C.They move to other
12、 fields free from insecticide.D.They never eat again those plants containing insecticid(4).Which of the following statements concerning banning GM foods is TRUE according to the passage?（分数：9.00）A.Underdeveloped countries have banned GM foods.B.Both Europe and the U.S. have banned GM foods.C.Most Eu
13、ropean countries have not banned GM foods.D.The United States has not banned GM foods.(5).What is the writers attitude to GM foods?（分数：9.00）A.We cannot tell from the passage.B.He thinks their benefits outweigh their risks.C.He thinks their risks outweigh their benefits.D.He thinks their benefits and
14、 risks are balancePassage TwoMost systems of medicine are based on theater. With leeches, acupuncture needles, vitamin pills or whatever stage props(道具) is appropriate for the time and culture, the healer artfully evokes the patients powers of self-suggestion, which are responsible for whatever heal
15、ing may occur.Western medicine operates on a different plane. For one thing, it has the most impressive props-expensive medicines, elaborate rituals and mysterious high-tech machines with a white-gowned cast to operate them. For another, it evokes the patients auto suggestive powers all the more for
16、cefully by pretending to ignore them. This mysterious gift of self-healing is cloaked(掩饰) with an anodyne label, the “placebo effect“, and recognized only as a nuisance likely to confound clinical trials. But the placebo(Latin for “I will please“) and its shadowy twin the nocebo(“I will harm“) are m
17、uch more than methodological problems: they lie at the heart of every interaction between doctor and patient.How they work no one knows. But the brain rules the body in many subconscious ways, including its control of the bodys major hormones and its subtle influence over the immune system. So its p
18、ossible that, in ways yet unknown, expectations about health or disease are sometimes translated into a bodily reaction that fulfills them.The power of these effects is hard to overstate. A rule of thumb is that 30 percent of patients in the placebo half of a drug trial(i.e, those who unknowingly re
19、ceive a dummy pill instead of the real thing) will experience an improvement in symptoms. But the proportion may be much higher. Just like real drugs, placebo pills can produce stronger effects in larger doses. Patients will report greater relief when given a larger pill, or two dummy capsules inste
20、ad of one.Doctors expectations also contribute to the awesome power of the placebo effect. In a study of tooth extractions, patients were given either a painkiller or sham drugs. Some dentists were assigned to give either drug, without knowing which, but other dentists knew they would be giving only
21、 sham drugs. The patients whose dentists thought they had at least a 50-50 chance of giving a painkiller suffered significantly less pain.Presumably, doctors transmit their expectations to the patient through subtle cues, often without knowing they are doing so. For this reason, all properly designe
22、d drug trials are double blind. But given that both groups can often guess from the side effects, even this precaution may not always crush the generation of expectancies.（分数：45.00）(1).Which of the following is NOT a feature of Western medicine?（分数：9.00）A.It reduces the patients self-healing powers.
23、B.It has the full support of high-tech machines.C.It is very expensive.D.It has complicated rituals.(2).What dose the term “the placebo effect“ (Lines 1-2, Par（分数：9.00）A.5) mean?A. It means the mind-troubling effect.B. It means the psychological effect.C. It means the harmful effect.D. It means the
24、theatrical effect.(3).What does “them“ (the last word in Paragraph 3) refer to?（分数：9.00）A.Clinical trials.B.The bodys major hormones.C.Expectations about health or disease.D.Many subconscious ways.(4).Why did the patients whose dentists thought they had at least a 50-50 chance of being given a paink
25、iller suffer significantly less pain?（分数：9.00）A.Because of doctors expectations.B.Because of the placebo effect.C.Because of the healing power of the medicine taken.D.Because of the excellent medical skills of the doctors.(5).What does the author mean by saying that for this reason, all properly des
26、igned drug trials are double blind (in the last paragraph)?（分数：9.00）A.The physician and the patient are both ignorant of the healing power of the medicine.B.The physician doesnt know whether the given pill is real or fake.C.The patient doesnt know whether the given pill is real or fake.D.Neither the
27、 physician nor the patient knows whether the given pill is real or fakPassage ThreeFew scenarios(情形,局面) provoke more hysteria(歇斯底里) than the one in which machines take over, especially when it involves machines replicating the arguably unique human capacity for language and thought. Not those anxiet
28、ies have kept us from trying to build smart machines. On the contrary, researchers have tried for decades to produce essay-grading software. But few have claimed the success that Landauer and his colleagues have-and none has applied such unorthodox(非正统的) assumptions.Traditionally, computer technique
29、s for analyzing written language relied on grammar and syntax. Since the 1960s, programmers have been designing software that searched for familiar features of good writing, such as sentence length, spelling, and the rhetorical signposts of argumentation-words like “might“, “therefore“, or “however“
30、. The goal was to get computers to “read“ texts with the aid of dictionaries, spell checks, and grammar software. Most of these efforts have been disappointing.But the technique Landauer, a professor at Colorado came up with, is an altogether different beast. His software completely ignores style, g
31、rammar, and syntax. In fact, it relies on none of the familiar rules of language at all. It concerns itself solely with the following question: Does the students essay use words appropriate to the subject matter? To answer this question, Landauers software performs a series of operations. First, it
32、assembles a customized database of texts on the assigned topic. It measures the spatial relationships among all the words in these texts, noting where each word appears and which other words it is near. The software then performs a similar analysis on the students essay. Finally, it compares the stu
33、dents essay with the texts in its database. The theory behind the method is this: For any given essay, good content is a function of using certain words in the vicinity of certain other words, and that accomplishment can be expressed numerically.It sounds too complicated(or too simple) to be any goo
34、d, but Landauer and his team claim their program can crank out grades as accurately as any professor. Indeed, flushed with the success of their experimental results, the psychologists have formed a company-Knowledge Analysis Technologies-to market their tool to schools. Theyve already signed up a pr
35、ofessor at Florida State University to test the grading machine in his classroom next fall.（分数：45.00）(1).The major difference between Landauers and traditional grading software lies in_（分数：9.00）A.the intended usersB.the underlying theoryC.the amount of database involvedD.the skills with which the so
36、ftware is programmed(2).We can conclude that the traditional grading software has been disappointing because_（分数：9.00）A.it focuses on the form of writingB.it analyzes the topic of writingC.it can only “read“ short textsD.it cannot recognize rhetorical devices(3).Landauers software determines the con
37、tent of an essay by _（分数：9.00）A.analyzing certain words in relation with other wordsB.recognizing the functions of words usedC.counting the number of words typically used in argumentD.comparing the number of words used in the database and those in an essay(4).Landauers software will be less effectiv
38、e if_（分数：9.00）A.an essay has a brand-new topicB.an essay is written by a writerC.an essay is very longD.an essay contains grammar errors(5).According to the last paragraph, which of the following statements is TRUE?（分数：9.00）A.Landauer and his team consider their work a success.B.Landauer and his tea
39、m are worried about their works market performance.C.Landauer and his team believe their work still leaves great room for improvement.D.Landauer and his team believe their work will put professor grading work to shamPassage FourBy Education, I mean the influence of the environment upon the individua
40、l to produce a permanent change in the habits of behavior, of thought and of attitude. It is being thus that all creatures are susceptible to the environment, and that man differs from the animals, and the higher animals from the lower. The lower animals are influenced by the enviromnent but not in
41、the direction of changing their habits. Their instinctive responses are few and fixed by heredity(遗传). When transferred to an unnatural situation, such an animal is led astray by its instincts. Thus the antlion whose instinct implies it to bore into loose sand by pushing backwards with abdomen, goes
42、 backwards on a plate of glass as soon as danger threatens, and endeavors, with the utmost exertions to bore into it. It knows no other mode of flight. If such a lonely animal is engaged upon a chain of actions and is interrupted, it either goes on vainly with the remaining action, as useless as cul
43、tivating an unsown field, or dies in helpless inactivity. Thus a net-making spider which digs a burrow and rims it with a bastion of gravel and bits of wood, when removed from a half finished home, will not begin again, though it will continue another burrow, even one made with a pencil.Advance in t
44、he scale of evolution along such lines as these could only be made by the emergence of creatures with more and more complicated instincts. Such beings we know in the ants and spiders. But another line of advance was destined to open out a much more far-reaching possibility of which we do not see the
45、 end perhaps even in man. Habits, instead of being born with(when they are called instincts but not habits at all) were left more and more to the formative influence of the environment, of which the most important factor was the parents who now cared for the young animal during a period of infancy i
46、n which vaguer instincts than these of the insects were molded to suit surroundings which might be considerably changed without harm.This means, one might at first imagine, that gradually heredity becomes less and environment more important. But this is hardly the truth and certainly not the whole t
47、ruth. For although fixed automatic responses like those of the insect-like creatures are no longer inherited, although selection for purification of that sort is no longer going on, yet selection for educability is very definitely still of importance. The ability to acquire habits can conceivably in
48、herit just as much as the definite responses to narrow situations. Besides, since a mechanism is now, for the first time, created by which the individual(in contradiction to the species) can be fitted to the envirornnent, the latter becomes, in another sense, less not more important. And finally, le
49、ss not the higher animals who possess the power of changing their environment by engineering feats and the like, a power possessed to some extent even by the beaver, and preeminently by man. Environment and heredity are in no case exchtsive but-always-supplementary factors.（分数：45.00）(1).Which of the following is the most suitable title for the passage?（分数：9.00）A.The Evolution of InsectsB.Environment and HeredityC.Education: The Influence of the EnvironmentD.The Instincts of Animals(2).What does the word “education“ in the first paragraph mea
