1、大学英语六级分类模拟题 452 及答案解析(总分：445.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：0，分数：0.00)二、Section A(总题数：1，分数：70.00)Why Teenagers Act CrazyA. Adolescence is practically synonymous in our culture with risk taking, emotional drama and all forms of strange behavior. Until very recently, the widely accepted expl
2、anation for adolescent angst has been psychological. Developmentally, teenagers face a number of social and emotional challenges, like starting to separate from their parents, getting accepted into a peer group and figuring out who they really are. It doesn“t take a psychoanalyst to realize that the
3、se are anxiety-provoking transitions. B. But there is a darker side to adolescence that, until now, was poorly understood: a surge during teenage years in anxiety and fearfulness. Largely because of a quirk (古怪) of brain development, adolescents, on average, experience more anxiety and fear and have
4、 a harder time learning how not to be afraid than either children or adults. C. Different regions and circuits of the brain mature at very different rates. It turns out that the brain circuit for processing fearthe amygdala (杏仁核)is precocious (早熟的) and develops way ahead of the prefrontal cortex (前额
5、皮质), the seat of reasoning and executive control. This means that adolescents have a brain that is wired with an enhanced capacity for fear and anxiety, but is relatively underdeveloped when it comes to calm reasoning. D. You may wonder why, if adolescents have such enhanced capacity for anxiety, th
6、ey are such novelty seekers and risk takers. It would seem that the two traits are at odds. The answer, in part, is that the brain“s reward center, just like its fear circuit, matures earlier than the prefrontal cortex. That reward center drives much of teenagers“ risky behavior. This behavioral par
7、adox also helps explain why adolescents are particularly prone to injury and trauma. The top three killers of teenagers are accidents, homicide and suicide. The brain-development lag has huge implications for how we think about anxiety and how we treat it. It suggests that anxious adolescents may no
8、t be very responsive to psychotherapy that attempts to teach them to be unafraid, like cognitive behavior therapy, which is zealously prescribed for teenagers. E. What we have learned should also make us think twiceand then someabout the ever rising use of stimulants in young people, because these d
9、rugs may worsen anxiety and make it harder for teenagers to do what they are developmentally supposed to do: Learn to be unafraid when it is appropriate to do so. Of course, most adolescents do not develop anxiety disorders, but acquire the skill to modulate (调节) their fear as their prefrontal corte
10、x matures in young adulthood, at around age 25. But up to 20 percent of adolescents in the United States experience a diagnosable anxiety disorder, like generalized anxiety or panic attacks, probably resulting from a mix of genetic factors and environmental influences. The prevalence of anxiety diso
11、rders and risky behavior (both of which reflect this developmental disjunction in the brain) have been relatively steady, which suggests to me that the biological contribution is very significant. F. One of my patients, a 32-year-old man, recalled feeling anxious in social gatherings as a teenager.
12、“It was viscerally (出自内心地) unpleasant and I felt as if I couldn“t even speak the same language as other people in the room,“ he said. It wasn“t that he disliked human company; rather, socializing in groups felt dangerous, even though intellectually he knew that wasn“t the case. He developed a strate
13、gy to deal with his discomfort: alcohol. When he drank, he felt relaxed and able to engage. Now treated and sober for several years, he still has a trace of social anxiety and still wishes for a drink in anticipation of socializing. G. Of course, we all experience anxiety. Among other things, it“s a
14、 normal emotional response to threatening situations. The hallmark of an anxiety disorder is the persistence of anxiety that causes intense distress and interferes with functioning even in safe settings, long after any threat has receded. We“ve recently learned that adolescents show heightened fear
15、responses and have difficulty learning how not to be afraid. In one study using brain M. R. I., researchers at Weill Cornell Medical College and Stanford University found that when adolescents were shown fearful faces, they had exaggerated responses in the amygdala compared with children and adults.
16、 H. The amygdala is a region buried deep beneath the cortex that is critical in evaluating and responding to fear. it sends and receives connections to our prefrontal cortex alerting us to danger even before we have had time to really think about it. Think of that split-second adrenaline (肾上腺素) surg
17、e when you see what appears to be a snake out on a hike in the woods. That instantaneous fear is your amygdala in action. Then you circle back, take another look and this time your prefrontal cortex tells you it was just a harmless stick. Fear learning lies at the heart of anxiety and anxiety disord
18、ers. This primitive form of learning allows us to form associations between events and specific cues and environments that may predict danger. Way back on the savanna (热带草原), for example, we would have learned that the rustle in the grass or the sudden flight of birds might signal a predatorand take
19、n the cue and run to safety. Without the ability to identify such danger signals, we would have been lunch long ago. But once previously threatening cues or situations become safe, we have to be able to re-evaluate them and suppress our learned fear associations. I. Another patient I saw in consulta
20、tion recently, a 23-year-old woman, described how she became anxious when she was younger after seeing a commercial about asthma (哮喘). “It made me incredibly worried for no reason, and I had a panic attack soon after seeing it,“ she said. As an older teenager, she became worried about getting too cl
21、ose to homeless people and would hold her breath when near them, knowing that “this was crazy and made no sense“. B. J. Casey, a professor of psychology and the director of the Sackler Institute at Weill Cornell Medical College, has studied fear learning in a group of children, adolescents and adult
22、s. Subjects were shown a colored square at the same time that they were exposed to an aversive (令人反感的) noise. The colored square, previously a neutral stimulus, became associated with an unpleasant sound and elicited a fear response similar to that elicited by the sound. J. What Dr. Casey and her co
23、lleagues found was that there were no differences between the subjects in the acquisition of fear conditioning. But when Dr. Casey trained the subjects to essentially unlearn the association between the colored square and the noisea process called fear extinctionsomething very different happened. Wi
24、th fear extinction, subjects are repeatedly shown the colored square in the absence of the noise. Now the square, also known as the conditioned stimulus, loses its ability to elicit a fear response. Dr. Casey discovered that adolescents had a much harder time “unlearning“ the link between the colore
25、d square and the noise than children or adults did. K. In effect, adolescents had trouble learning that a cue that was previously linked to something aversive was now neutral and “safe“. If you consider that adolescence is a time of exploration when young people develop greater autonomy, an enhanced
26、 capacity for fear and a more persistent memory for threatening situations are adaptive and would confer survival advantage. In fact, the developmental gap between the amygdala and the prefrontal cortex that is described in humans has been found across mammalian species, suggesting that this is an e
27、volutionary advantage. This new understanding about the neurodevelopmental basis of adolescent anxiety has important implications, too, in how we should treat anxiety disorders. One of the most widely used and empirically supported treatments for anxiety disorders is cognitive behavior therapy, a fo
28、rm of extinction learning in which a stimulus that is experienced as frightening is repeatedly presented in a nonthreatening environment. If, for example, you had a fear of spiders, you would be gradually exposed to them in a setting where there were no dire consequences and you would slowly lose yo
29、ur arachnophobia (蛛蛛恐惧症). The paradox is that adolescents are at increased risk of anxiety disorders in part because of their impaired ability to successfully extinguish fear associations, yet they may be the least responsive to desensitization (脱敏) treatments like cognitive behavior therapy precise
30、ly because of this impairment. L. But we do know this Adolescents are not just carefree novelty seekers and risk takers; they are uniquely vulnerable to anxiety and have a hard time learning to be unafraid of passing dangers. Parents have to realize that adolescent anxiety is to be expected, and to
31、comfort their teenagersand themselvesby reminding them that they will grow up and out of it soon enough.（分数：70.00）(1).People suffering from an anxiety disorder tend to have enduring anxious feelings after any threat has faded.（分数：7.00）(2).For teenagers, the region for reasoning in the brain develops
32、 slower than the brain circuit for processing fear and anxiety.（分数：7.00）(3).That the amygdala and the prefrontal cortex in mammals mature at different speeds is an evolutionary advantage.（分数：7.00）(4).Alcohol helps some people to relax when they feel anxious in social activities.（分数：7.00）(5).The earl
33、ier maturity of the reward center partly accounts for adolescents“ risky behavior.（分数：7.00）(6).Adolescents have to experience a series of anxiety-provoking challenges.（分数：7.00）(7).Parents should remind their kids that adolescent anxiety is normal and can be got over soon.（分数：7.00）(8).Researchers fou
34、nd teenagers were prone to get trouble in unlearning the negative feelings linked to the conditioned stimulus.（分数：7.00）(9).Most teenagers are able to control fear as their prefrontal cortex fully develops in their mid-twenties.（分数：7.00）(10).The amygdala delivers information about danger to the prefr
35、ontal cortex as soon as the danger comes.（分数：7.00）三、Section B(总题数：0，分数：0.00)四、Passage One(总题数：3，分数：162.00)The fridge is considered a necessity. It has been so since the 1960s when packaged food first appeared with the label: “store in the refrigerator.“ In my fridgeless fifties childhood, I was fed
36、well and healthily. The milkman came daily, the grocer, the butcher, the baker, and the ice-cream man delivered two or three times a week. The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes. Nothing was wasted, and we were never troubled by rotten food. T
37、hirty years on food deliveries have ceased, flesh vegetables are almost unobtainable in the country. The invention of the fridge contributed comparatively little to the art of food preservation. A vast way of well-tried techniques already existednatural cooling, drying, smoking, salting, sugaring, b
38、ottling. What refrigeration did promote was marketingmarketing hardware and electricity, marketing soft drinks, marketing dead bodies of animals around the globe in search of a good price. Consequently, most of the world“s fridges are to be found, not in the tropics where they might prove useful, bu
39、t in the wealthy countries with mild temperatures where they are climatically almost unnecessary. Every winter, millions of fridges hum away continuously, and at vast expense, busily maintaining an artificially-cooled space inside an artificially-heated housewhile outside, nature provides the desire
40、d temperature free of charge. The fridge“s effect upon the environment has been evident, while its contribution to human happiness has been insignificant, If you don“t believe me, try it yourself, invest in a food cabinet and turn off your fridge next winter. You may miss the hamburgers, but at leas
41、t you“ll get rid of that terrible hum.（分数：20.00）(1).The statement “In my fridgeless fifties childhood, I was fed well and healthily.“ (Line 1, Para. 2) suggests that _.（分数：4.00）A.the author was well-fed and healthy even without a fridge in his fiftiesB.the author was not accustomed to use fridges ev
42、en in his fiftiesC.there was no fridge in the author“s home in the 1950sD.the fridge was in its early stage of development in the 1950s(2).Why does the author say that nothing was wasted before the invention of fridges?（分数：4.00）A.People would not buy more food than was necessary.B.Food was delivered
43、 to people two or three times a week.C.Food was sold fresh and did not get rotten easily.D.People had effective ways to preserve their food.(3).Who benefited the least from fridges according to the author?（分数：4.00）A.Inventors.B.Consumers.C.Manufacturers.D.Travelling salesmen.(4).Which of the followi
44、ng phrases in the fifth paragraph indicates the fridge“s negative effect on the environment?（分数：4.00）A.“Hum away continuously“.B.“Climatically almost unnecessary“.C.“Artificially-cooled space“.D.“With mild temperatures“.(5).What is the author“s overall attitude toward fridges?（分数：4.00）A.Neutral.B.Cr
45、itical.C.Objective.D.Compromising.In a country with a shrinking population, the latest trend in Germany“s higher education is something of a mystery: the number of universities and academic programs is rising. The growth is the sharpest for professional graduate schools, where the number has soared
46、from practically zero in 2003 to 130 now, in fields ranging from law and business to clinical counseling and education. But there is one obvious problem: not enough students are signing up. The German government says that nearly half of professionally oriented programs, aside from law schools, have
47、yet to fill their stated student capacity. And the problem has been especially acute in graduate programs in education. Interest in many professional schools has been less than overwhelming, said Markus Zimmermann, an executive senior consultant at the Germany Research Institute in Berlin, which is
48、affiliated with Berliner Banking Corp. “German universities tend torolloutprogramswithout having a good grasp of the needs in the marketplace,“ said Mr. Zimmermann, who watches Germany“s higher education. “When they start a program, they assume there will be students.“ In Germany, the need for gradu
49、ate programs seems undeniable: lifetime employment is crumbling, employers are committing less time and money to training young workers, and social problems are becoming more complex, increasing the need for experts. Setting up graduate programs in education was the universities, answer to a growing dissatisfaction with the primary and secondary school system. With the accreditation (批准) of the Ministry of Education, 19 universities launched professionally oriented graduate programs in teacher education, seeking approximately 700 students in total. Seven more schools introduce
