1、大学英语四级分类模拟题 506及答案解析(总分：268.50，做题时间：90 分钟)一、Part Writing(总题数：1，分数：106.50)1.Directions : For this part, you are allowed 30 minutes to write a short essay. You should start your essay with a brief description of the picture and then express your views on the burden children are facing. You should writ
2、e at least 120 words but no more than 180 words. （分数：106.50）_二、Part Reading Compr(总题数：0，分数：0.00)四、Passage One(总题数：1，分数：71.00)Cleaning up our air may have made us healthier. A new analysis shows that the number of storms falls when pollution rises, and increases when pollution drops. Further tighteni
3、ng of present pollution controls “could reduce aerosols (气溶胶；悬浮颗粒) so quickly that we have record numbers of tropical storms for the next decade or two“, says Nick Dunstone of the Met Office Hadley Centre in Exeter, UK. Earlier studies found no connection between storm numbers and aerosols“ ability
4、to cool the surface by scattering light in the open air. But aerosols also increase the brightness and lifetime of low-level marine clouds. When Nick Dunstone of the Met Office Hadley Centre in Exeter, UK, added this effect into his climate models, the simulated clouds cooled the surface more than e
5、xpected. Historically, this cooling effect has been strongest in the north Atlantic. Cooling the north Atlantic reduces the energy available to power hurricanes. It also shifts rising and falling air currents further south, increasing wind shear in the Atlantic hurricane nursery. This extra wind she
6、ar tears nascent storms apart before they can gain strength. In this way, Dunstone says, changes in aerosol emissions appear to drive cyclical variations in north Atlantic tropical storms. These variations have long been attributed to natural variations in ocean circulation. Throughout the 20th cent
7、ury, aerosol emissions increased with industrialization and decreased in economic slumps. Tropical storms were frequent from the 1930s through to the 1950s, but rarer in the better economic times of the 1960s to mid-1990s. Then pollution controls reduced aerosol levels, and Atlantic hurricanes came
8、roaring back, with 19 in 1995, a record 28 in 2005, and 19 in each of the past three years. Dunstone expects the increase to continue for another two decades. After that, global warming may begin to reduce the number of tropical storms, by warming the air and thus reducing the temperature difference
9、 between the sea surface and the atmosphere. It is not clear whether aerosols affect the intensity of storms.（分数：71.00）(1).What can we learn from the first two paragraphs?（分数：14.20）A.The number of storms is inversely proportional to pollution index.B.The number of storms is related to aerosols“ abil
10、ity to cool the surface.C.Aerosols increase the brightness and lifetime of marine clouds.D.Aerosols cool the surface by gathering light in the open air.(2).According to the passage, cooling the north Atlantic _.（分数：14.20）A.provides energy to power hurricanesB.changes rising and falling air currents
11、further southC.hinders wind shearD.reduces the pollution index(3).What does the word “nascent“ (Para. 3) mean?（分数：14.20）A.Powerful.B.Earlier.C.Horrible.D.Small.(4).Which of the following is the factor that influences aerosol emissions?（分数：14.20）A.Cyclical variations in north Atlantic tropical storms
12、.B.Intensity of storms.C.The process of industrialization.D.The natural variations in ocean circulation.(5).Which of the following can be inferred from the passage?（分数：14.20）A.Because of global warming, the number of storm will increase.B.It is not clear whether aerosols affect the number of storms.
13、C.The cooling effect has been strongest in the Atlantic.D.The number of tropical storms is more in 1930s to the 1950s than in 1960s to mid-1990s.五、Passage Two(总题数：1，分数：71.00)Working out how an extinct animal behaved when it was alive is tricky. But it is not always impossible, as Joseph Peterson and
14、 Collin Dischler of the University of Wisconsin explained on October 17th to the Society of Vertebrate Palaeontology meeting held in Raleigh, North Carolina. Pachycephalosaurs lived 65 million years ago. As their name suggests, they had large, bony, domed or round heads. For years, it was assumed th
15、ey used these to attack one another in the way that rams (公羊) do now. Recently, though, a second suggestion has surfacedthat rather than for fighting, the domes were for show; the dinosaur equivalent of a peacock“s tail. Dr. Peterson and Dr. Dischler put these two theories into a head-to-head compet
16、ition. To do so, they studied 102 pachycephalosaur bones, of various species. They found that 23 of these bones had pits in them, and that these pits were similar both to each other and to those found in the bones of living animals that attack each other with their heads. That supported the head-but
17、ting theory. The clincher, though, came when they created computerised models of pachycephalosaur bones and mapped the damage from each of their pitted specimens on to these virtual bones. When they did this, they found that the pits were clusteredexactly as might be expected if they were the result
18、 of animals deliberately aiming at each other. Intriguingly, they found two patterns of clustering. Those pachycephalosaurs with highly domed heads had pits on both the fronts and the backs of their bones. Those whose domes were lower had them only on the fronts. This suggests the two sorts of anima
19、l fought in different ways. Low-domes, it seems, simply charged at each other. High-domes did that too. But they also engaged in head-to-head wrestling of a sort that allowed them to get behind their opponents“ bones and do damage from the rear, in the way that modem bison do. None of which proves t
20、hat pachycephalosaurs did not show off their stuff with their domes as well, just as a stag will often show off its antlers before engaging in combat, in order to give a less well-endowed rival the opportunity to withdraw. But it does demonstrate that the domes were serious weapons, not mere showy c
21、lothing of fashion.（分数：71.00）(1).According to the passage, it is usually _ to prove the behavior of extinct animals?（分数：14.20）A.no wayB.not hardC.hardD.not impossible(2).Which one can be chosen as the best Chinese translation forpachycephalosaur ?（分数：14.20）A.原始恐龙B.恐龙斗士C.肿头龙D.孔雀龙(3).How do scientists
22、 do with two different kinds of sayings of the pachycephalosaur“s dome?（分数：14.20）A.They insist on their own opinion of the pachycephalosaur“s dome.B.They study both of the theory with equal weight.C.They give up both of the sayings.D.They do not care much about the sayings at all.(4).What does the w
23、ord clincher in the first sentence of paragragh 2 mean?（分数：14.20）A.A tool used to pick up nails or bolts.B.An argument that is conclusive.C.A scientist“s name.D.A computer program which is useful to the study of pachycephalosaur.(5).What is the author“s perspective about the pachycephalosaur“s domes
24、?（分数：14.20）A.They are serious weapons.B.They are decorations to show its beauty as peacock“s tail.C.They are candidate for scientific study.D.They are both weapons and decorations.六、Part Translation(总题数：1，分数：20.00)2.在人们眼中，公务员工作可以提供稳定的收入、良好的社会地位和较好的福利。自 1995年国家公务员考试推行以来，这一考试日渐升温，使之成为中国竞争最激烈的考试。另外，毕业生
25、数量骤增，使他们很难找到一份满意的工作。所以，很多大学生更愿意在毕业之后报考公务员。但是，大学生应该制订一个清晰的职业生涯规划，而不应该盲目地报考公务员。 （分数：20.00）_大学英语四级分类模拟题 506答案解析(总分：268.50，做题时间：90 分钟)一、Part Writing(总题数：1，分数：106.50)1.Directions : For this part, you are allowed 30 minutes to write a short essay. You should start your essay with a brief description of th
26、e picture and then express your views on the burden children are facing. You should write at least 120 words but no more than 180 words. （分数：106.50）_正确答案：()解析：参考范文 Too Many Burdens to BearAs is illustrated in the picture, the newborn baby is expected to learn to walk, speak and read at 12-month old,
27、 an age when babies can barely make meaningful utterances. This picture vividly shows that fierce competition in modern time is imposing heavier and heavier burdens on children, who are now deprived of the right to enjoy a carefree childhood. It is not difficult to observe the heavy pressures impose
28、d on children nowadays. The time has come to change our philosophy of education. On the one hand, too many pressures are likely to twist children“s mental health, which is definitely detrimental to their long-term development. On the other hand, readiness to learn should be prioritized over other fa
29、ctors in that interest is the most potent driving force to learn. One is more likely to succeed when he is motivated than when he is forced to learn. It is true that children should start learning at an early age to keep abreast with their peers. Nonetheless, they should not bear excessive pressures
30、, which will hinder their growth.二、Part Reading Compr(总题数：0，分数：0.00)四、Passage One(总题数：1，分数：71.00)Cleaning up our air may have made us healthier. A new analysis shows that the number of storms falls when pollution rises, and increases when pollution drops. Further tightening of present pollution cont
31、rols “could reduce aerosols (气溶胶；悬浮颗粒) so quickly that we have record numbers of tropical storms for the next decade or two“, says Nick Dunstone of the Met Office Hadley Centre in Exeter, UK. Earlier studies found no connection between storm numbers and aerosols“ ability to cool the surface by scatt
32、ering light in the open air. But aerosols also increase the brightness and lifetime of low-level marine clouds. When Nick Dunstone of the Met Office Hadley Centre in Exeter, UK, added this effect into his climate models, the simulated clouds cooled the surface more than expected. Historically, this
33、cooling effect has been strongest in the north Atlantic. Cooling the north Atlantic reduces the energy available to power hurricanes. It also shifts rising and falling air currents further south, increasing wind shear in the Atlantic hurricane nursery. This extra wind shear tears nascent storms apar
34、t before they can gain strength. In this way, Dunstone says, changes in aerosol emissions appear to drive cyclical variations in north Atlantic tropical storms. These variations have long been attributed to natural variations in ocean circulation. Throughout the 20th century, aerosol emissions incre
35、ased with industrialization and decreased in economic slumps. Tropical storms were frequent from the 1930s through to the 1950s, but rarer in the better economic times of the 1960s to mid-1990s. Then pollution controls reduced aerosol levels, and Atlantic hurricanes came roaring back, with 19 in 199
36、5, a record 28 in 2005, and 19 in each of the past three years. Dunstone expects the increase to continue for another two decades. After that, global warming may begin to reduce the number of tropical storms, by warming the air and thus reducing the temperature difference between the sea surface and
37、 the atmosphere. It is not clear whether aerosols affect the intensity of storms.（分数：71.00）(1).What can we learn from the first two paragraphs?（分数：14.20）A.The number of storms is inversely proportional to pollution index. B.The number of storms is related to aerosols“ ability to cool the surface.C.A
38、erosols increase the brightness and lifetime of marine clouds.D.Aerosols cool the surface by gathering light in the open air.解析：考点 文章细节 解析 根据题干，该题应定位到本文的前两段。A 选项中 inversely proportional意为“成反比”，也就是说风暴数量和污染指数是成反比的，这正是文章的中心思想，在第一段中也有详细表述，所以 A选项正确。B 选项指出风暴的数量是和气溶胶冷却海洋表面空气的能力相关的。而第二段第一句指出气溶胶通过散射户外光线来冷却海洋
39、表面空气，而早期的研究并未发现风暴的数量和气溶胶的这种能力有关系。所以 B选项不对。C 选项“气溶胶增加了海洋云的亮度和寿命”，第二段第二句对其进行了描述，但第二句描述的是增加了低位海洋云层的亮度和寿命，所以 C选项也不正确。D 选项是对第二段第一句的曲解，第二段第一句指出气溶胶通过对户外光线的散射来冷却海洋表面空气，而 D选项指出通过聚集户外光线来冷却海洋表面空气。所以 D选项也不正确。(2).According to the passage, cooling the north Atlantic _.（分数：14.20）A.provides energy to power hurrican
40、esB.changes rising and falling air currents further south C.hinders wind shearD.reduces the pollution index解析：考点 文章细节 解析 根据题干可以将该题定位至第三段。第三段指出：北大西洋表面空气的冷却减少了飓风生成所需的能量，并将上升和下降气流进一步南推，增加大西洋飓风带的风切，从而切断刚刚形成的风暴。Dunstone说，通过这种方式，气溶胶排放量的变化似乎促使了北大西洋热带风暴的周期性变化，这些变化一直都被归结为海洋环流的自然变异。A 选项指出北大西洋表面空气的冷却为飓风的形成提供了动
41、力，这与第三段中北大西洋表面空气的冷却增大了风切变，而这种额外的风切变切断形成初期的风暴不符，所以不能选。B 选项正确。C 选项指出北大西洋表面空气的冷却阻止了风切变，这也不正确。D 选项认为北大西洋表面空气的冷却降低了污染指数，这并未在文章中得到明确说明，所以也不正确。(3).What does the word “nascent“ (Para. 3) mean?（分数：14.20）A.Powerful.B.Earlier. C.Horrible.D.Small.解析：考点 词义 解析 回归到第三段第三句，This extra wind shear tears nascent storms
42、apart before they can gain strength。they 指的是 storms。在风暴变强大前，也就是在风暴还处于形成初期的状态下就将其切断，所以 nascent的同义词是 B。该题容易误选成 D选项 small，但该句并没有明确表示风暴的大小，而是说在它形成的初期和力量增强前。(4).Which of the following is the factor that influences aerosol emissions?（分数：14.20）A.Cyclical variations in north Atlantic tropical storms.B.Inten
43、sity of storms.C.The process of industrialization. D.The natural variations in ocean circulation.解析：考点 文章细节 解析 根据题干可以将该题定位至第四段，第四段的第一句话就道出了答案。“气溶胶排放随着工业化的进程而增加，在经济衰退时又有所减少”，所以 C选项正确。A、B 和 D选项都不是影响气溶胶排放量的因素。(5).Which of the following can be inferred from the passage?（分数：14.20）A.Because of global warm
44、ing, the number of storm will increase.B.It is not clear whether aerosols affect the number of storms.C.The cooling effect has been strongest in the Atlantic.D.The number of tropical storms is more in 1930s to the 1950s than in 1960s to mid-1990s. 解析：考点 推断 解析 A 选项说因为全球变暖，风暴的数量将会增加。文章最后一段第二句指出全球变暖可能开
45、始造成热带风暴数量的减少。所以 A选项不正确。B 选项说气溶胶是否影响了风暴的数量仍未确定。文章开头就表述了污染指数与风暴数量的关系，也就说明了气溶胶与风暴数量的关系。最后一段的末句说，气溶胶对风暴强度的影响还未确定，不是说对其数量的影响，所以 B选项可以排除。根据第二段最后一句的 north Atlantic可以排除 C选项。D 选项可以根据第四段第二句得到验证。五、Passage Two(总题数：1，分数：71.00)Working out how an extinct animal behaved when it was alive is tricky. But it is not al
46、ways impossible, as Joseph Peterson and Collin Dischler of the University of Wisconsin explained on October 17th to the Society of Vertebrate Palaeontology meeting held in Raleigh, North Carolina. Pachycephalosaurs lived 65 million years ago. As their name suggests, they had large, bony, domed or ro
47、und heads. For years, it was assumed they used these to attack one another in the way that rams (公羊) do now. Recently, though, a second suggestion has surfacedthat rather than for fighting, the domes were for show; the dinosaur equivalent of a peacock“s tail. Dr. Peterson and Dr. Dischler put these
48、two theories into a head-to-head competition. To do so, they studied 102 pachycephalosaur bones, of various species. They found that 23 of these bones had pits in them, and that these pits were similar both to each other and to those found in the bones of living animals that attack each other with their heads. That supported the head-butting theory. The clincher, though, came when they created computerised models of pachycephalosaur bones and mapped the damage from each of their pitted specimens on to these virtual bones. When they did this, they found that the pits were
