1、大学英语四级改革适用（阅读）模拟试卷 130及答案与解析 Section A 0 When medal-winning athletes return home from the Olympic Games, their fame may be short-lived, but they can look forward to a long life. A new study has found that Olympic medalists live an average of 2.8 years longer than the【 C1】 _of us, whether theyre a gy
2、mnast, golfer, runner, or athlete in any other event. The study used data on 15 174 male and female athletes who won medals in Olympic Games since 1896 and found that 30 years after any【 C2】 _Olympics, 8% more medalists were alive than others from their country and birth year. The effect, a second s
3、tudy concluded, wasnt【 C3】 _seen in Olympic athletes who【 C4】 _in high-endurance or high-intensity events. Researchers found no difference in mortality between cyclists, rowers, tennis stars, and cricket【 C5】 _. But the factor that did make a difference: whether a sport had high levels of physical【
4、C6】 _and collisions. Olympians in sports with higher bodily collision, such as boxing, had an 11% higher mortality【 C7】 _than those in sports with minimal collisions. Both studies were published online today in British Medical Journal. The researchers【 C8】 _that medalists could live longer because o
5、f their intensive training, exercise levels throughout life, or because their success leads to【 C9】 _wealth or education levels, but more research will be needed to【 C10】_what is at play. A)assume F)hardly K)participated B)attracted G)healthy L)players C)contact H)increased M)quality D)determine I)i
6、nfluence N)rest E)given J)just O)risk 1 【 C1】 2 【 C2】 3 【 C3】 4 【 C4】 5 【 C5】 6 【 C6】 7 【 C7】 8 【 C8】 9 【 C9】 10 【 C10】 Section B 10 Ecosystems in and out of Balance A)It is known that ecosystems have a structure consisting of producers(green plants which use light energy to produce living matter fr
7、om non-living matter in the environment), consumers(all the animals which feed directly or indirectly on the green plants), and decomposers(分解体 )(bacteria and fungi that change the dead organic material back into simple raw materials which can then again be used by the producers). This structure, wh
8、ich is necessary to maintain the flow of energy and nutrients through the system, consists of the interactions between hundreds or even thousands of different kinds of plants, animals, and microbes which grow, reproduce and die in a never-ending cycle. B)At this point, we might ask ourselves, since
9、ecosystems consist of interactions between reproduction populations, what prevents one species(kind)of organism from reproducing in such numbers that it overcomes and eliminates other species? In other words, what are the factors that maintain the structure, or balance, of that ecosystem? To answer
10、the question we must first recognize that the idea of ecosystem balance is relative. In fact, ecosystems are always changing and adjusting. The relative degree of balance is the main factor in determining the rate of change. A well-balanced system will change very slowly, perhaps unnoticeably, in th
11、e course of direct human experience. An unbalanced system changes more or less rapidly; the greater the imbalance, the more rapid the change. It follows that if a change is made in one or more of the factors that affect balance, the ecosystem itself will also change. C)One way of viewing ecosystem c
12、hange and balance is in terms of the two factors: biotic potential and environmental resistance. The biotic potential of a species is its capacity for reproducing itself; in a general sense it is the combination of all the factors that permit its kind to become more numerous. Birth rate is an obviou
13、s factor, but it is only one. Given favorable conditions, every species has a biotic potential to increase its population. For example, a pair of frogs has the biotic potential to produce several hundred offspring in one season and each offspring in turn could potentially produce several hundred mor
14、e. D)The fact that populations in nature generally do not “explode“ in numbers is not due to limits in biotic potential, but to a second factor, environmental resistance. The environmental resistance facing each species is the combination of all the factors that limit the survival of its members. Th
15、ese factors are similar for both plants and animals. Thus, there is a relationship between biotic potential and environmental resistance. If the environmental resistance for a species is less than its biotic potential, its members will increase; if the environmental resistance is greater than biotic
16、 potential, then its numbers will decrease. In a stable ecosystem, the biotic potential of each species is evenly balanced by environmental resistance. E)Now lets look at ourselves as a species in relation to ecosystem balance. Modern scientists believe that humankind, like other animals, evolved th
17、rough millions of years of changes and adaptations to the environment. Despite this similarity with other creatures, however, the evolution of humankind differs from that of other species in one important and unique way. In other species evolution has led to specialization, both in the species abili
18、ties and in its place within the environmental structure. For example, the giraffe(长颈鹿 )is marvelously adapted to grazing on treetops but, as such, it is also specialized and thus restricted to grazing on trees and shrubs(灌木 ). The same is true for countless other species. For humankind the reverse
19、is true. Our evolution had led to a very generalized capability. Our highly developed intelligence and ability to make and handle tools mean that we can do virtually anything. Rather than evolving into a specialized role in balance with natural enemies, competitive species and environmental factors,
20、 humans evolved in such a way that we are capable of moving into every environment on Earth and even into space. Said another way, we see in humankind a tremendous imbalance between biotic potential and environmental resistance. The result is the rapidly increasing world population, frequently refer
21、red to as the population explosion. Further, to support our growing population, natural ecosystems are being increasingly displaced by human habitations, agriculture, and other human-supporting activities. F)From the viewpoint of evolutionary history, the spreading of human beings over the earth can
22、 be looked at as a natural process, the latest of many waves of change that have occurred since the earliest beginnings of life on this planet. Unfortunately, there is nothing in ecological or evolutionary theory to support the view that humans will be the last or even a long-lasting “wave“. In fact
23、, there are many indications that the human wave, at least that of humans in a technological society, may be relatively short lived. Why is it so? First the rate and degree of many changes being brought about by humans are extreme. Previous evolutionary changes have occurred over the course of many
24、millions of years. Thus the slow process of readaptation and development of new species more or less balanced extinctions, and ecosystems remained in relative balance throughout the course of change. In contrast, the significant changes brought about by humans have occurred in only the last 200 year
25、s. G)The result is that extinctions are occurring at a distressingly fast rate, a rate which is more than likely to increase in the future. Changes in the biosphere are occurring so rapidly that we have no way of accurately predicting the outcome. Many ecologists are concerned that the basic balance
26、s within the biosphere will be so altered that all life on earth, including human life, will be disrupted. H)Second, there is danger in the simplicity of the human ecosystem. Based as it is on relatively few species of agricultural crops and animals, the human ecosystem is inherently unstable. Agric
27、ultural production is only tenuously(细微地 )balanced by the massive use of powerful chemicals to control pests, and these chemicals are causing ecological upsets that frequently make pest problems even worse. Also, plant scientists warn that an outbreak of crop disease for which we do not have a cure
28、could wipe out a significant portion of the world food supply in one season. I)Third, there are many indications that present human expansion is resulting in overgrazing of vast areas of the earths surface. Overgrazing occurs when plant-eating populations expand to the point when they eat the vegeta
29、tion faster than it can produce and, consequently, destroy it. J)In conclusion, there is no way that the human species can avoid facing the ultimate checks and balances that apply to other species and ecosystems. Fortunately, however, ecological realities need not be ignored. We as humans do have th
30、e unique evolutionary traits of exceptional intelligence and technological capability. We have the potential to use these traits to make adjustments in our societies and lifestyles to live within ecological limits and in balance with the rest of the biosphere. 11 A tremendous imbalance between bioti
31、c potential and environmental resistance in human beings leads to a massive population growth. 12 There are no absolutely balanced ecosystems since they are always changing. 13 Intelligence and technological capability will enable human beings to survive and be compatible with other species. 14 Scie
32、ntists believe that a large amount of the world food supply may be destroyed due to an outbreak of incurable crop disease. 15 The structure of an ecosystem is made up of producers, consumers and decomposers. 16 It is environmental resistance that prevents populations of a species from rocketing. 17
33、The rate and degree of changes being brought about by humans make it hard for the ecosystems to keep balanced. 18 Overgrazing of vast areas of the earths surface results from present human expansion. 19 The similarity between human beings and other animals in respect to evolution is that they have c
34、hanged and adjusted to the situations. 20 A change made in one or more of the factors that affect balance could result in changes in the ecosystem as a whole. Section C 20 Telecommuters fall into two camps. Some sit on the sofa watching daytime soaps, pausing occasionally to check their BlackBerrys.
35、 Most, however, do real work, undistracted by meetings and talkative colleagues. In the future more people will work from home. With office space in London and New York so costly, many firms save money by encouraging staff to work in their pyjamas. Instead of having to bury their noses in strangers
36、armpits on crowded trains, they can work via e-mail, Skype and virtual private networks. Yet, in research published in MIT Sloan Management Review, Daniel Cable of the London Business School shows that telecommuters are less likely to be promoted. In one experiment, subjects were asked to judge scen
37、arios(场景 )in which the only difference was whether the employee was at his office desk or at home. Managers rated those at the office to be more dependable and industrious, regardless of the quality of their work. Visibility creates the illusion of value. Being the last to leave the office impresses
38、 bosses, even if you are actually larking around(胡闹 )on Facebook. Oddly, this holds true at firms that explicitly encourage staff to work from home. Many Californian tech firms asked employees not to come to the office too often; yet bosses unconsciously penalised those who obeyed. Remote workers un
39、derstand this. Many frequently sent their bosses progress reports to prove they are on the job. A fifth of the workers in the study admitted to leaving an e-mail or voice mail early or late in the day. Still, many are not as smart as they think. Some choose a Monday or Friday to work at home. That,
40、says Mr. Cable, makes others think they are keen to extend the weekend. A culture of presenteeism(全勤主义 )hurts working mothers most. Many women(and some men)work from home to allow themselves the flexibility to pick up kids from school. That need not mean they produce less; only that they do it at a
41、time and a place of their own choosing. Some firms, such as Best Buy, an electronics retailer, recognise this and try hard to evaluate staff solely on performance. But this is not easy. Intangibles such as teamworking skills matter, too. Mr. Cable thinks homeworking will lose its stigma(耻辱 )only whe
42、n most people do it. Or perhaps when the boss is telecommuting, too. 21 What is most likely the main cause of the increasing number of telecommuters? （ A） Attractive daytime soaps. （ B） Annoying talkative colleagues. （ C） High-tech mobile phones. （ D） Increasing location rents. 22 Why do telecommute
43、rs probably get fewer opportunities for promotion? （ A） Their quality of work is worse. （ B） They are inefficient at their work. （ C） They are misjudged by the bosses. （ D） They spend less time working. 23 What does the example of many California tech firms prove? （ A） Working at home is impractical
44、 in tech firms. （ B） Bosses often dont keep their promises. （ C） Employees should judge when to obey. （ D） Employees presence at office raises their value. 24 What do wise telecommuters do to prove that they are on the job? （ A） They give timely accounts of their work progress to their bosses. （ B）
45、They check their e-mails and voice mails every day. （ C） They discuss the work with their bosses. （ D） They spend some time working on weekends. 25 What is the biggest disadvantage of working at home according to the last paragraph? （ A） The traditional working culture can be hurt. （ B） Mothers work
46、 may be disrupted by their kids. （ C） Retailers cant get enough on-site employees. （ D） Employees may lack chances to develop certain skills. 25 Immigration is regarded by the public as the biggest issue facing British society, a major new survey taking stock of the state of the country reveals. One
47、 in three people believes tension between immigrants and people born in the UK is the major cause of division, while well over half regard it as one of the top three causes. Over the past two decades, both immigration and emigration have increased to historically high levels, with those entering the
48、 country exceeding those leaving by more than 100 000 in every year since 1998. Yet the survey in a report by the think tank British Future also suggests the country is, at heart, tolerant of those who come to its shores. While one in four thinks being born here is important to being British, two-th
49、irds of people believe the welfare state should be open to those born abroad who have contributed to society and play by the rules. The poll results are being released as communities secretary Eric Pickles prepares to give a major speech in which he will announce further efforts to aid integration. Pickles will say that a mastery of English is the key to social mobility and essential if people of different generations want to get on. He will stress that a shared language is vital for our economy. And he will highlight
