1、大学英语六级模拟试卷 669及答案与解析 一、 Part I Writing (30 minutes) 1 Directions: For this part, you are allowed 30 minutes to write a composition on the topic: Salary or Interest. You should write at least 150 words following the outline given below: 1. 如今的大学毕业生面临的职 业选择：兴趣重要还是工资重要 2. 你的观点 3. 结论 Salary or Interest
2、二、 Part II Reading Comprehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-4, mark： Y (for YES) if the statement agrees with the information given in the pas
3、sage; 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. 1 Lessons in Longevity This year, the number of pensioners in the UK exceeded the number of minors for the first time in history. Thats remarkable in
4、 its own right, but the real “population explosion“ has been among the oldest of the old the centenarians (百岁老人 ). In fact, this is the fastest-growing demographic in much of the developed world. In the UK, their numbers have increased by a factor of 60 since the early 20th century. And their ranks
5、are set to swell even further, thanks to the ageing baby-boomer generation: by 2030 there will be about a million worldwide. These trends raise social, ethical and economic dilemmas. Are medical advances artificially prolonging life with little regard for the quality of that life? Old age brings an
6、increased risk of chronic disease, disability and dementia, and if growing numbers of elderly people become dependent on state or familial support, society faces skyrocketing costs and commitments. This is the dark cloud outside the silver lining of increasing longevity. Yet researchers who study th
7、e oldest old have made a surprising discovery that presents a less bleak vision of the future than many anticipate. It is becoming clear that people who break through the 90-plus barrier represent a physical elite, markedly different from the elderly who typically die younger than them. Far from gai
8、ning a longer burden of disability, their extra years are often healthy ones. They have a remarkable ability to live through, delay or entirely escape a host of diseases that kill off most of their peers. Super-centenarians people aged 110 or over are even better examples of ageing gracefully. The a
9、verage super-centenarian had freely gone about their daily life until the age of 105 or so, some 5 to 10 years longer even than centenarians, who are themselves the physical equivalent of people 8 to 10 years their junior. This isnt just good news for the oldest old and for society in general; it al
10、so provides clues about how more of us might achieve a long and healthy old age. One of the most comprehensive studies comes from Denmark. In 1998, Kaare Christensen at the University of Southern Denmark, in Odense, exploited the countrys exemplary registries to contact every single one of the 3,600
11、 people born in 1905 who was still alive. Assessing their health over the subsequent decade, he found that the proportion of people who managed to remain independent throughout was constantly around one-third of the total: each individual risked becoming more infirm, but the unhealthiest ones passed
12、 away at earlier ages, leaving the strongest behind. In 2005, only 166 of the people in Christensens sample were alive, but one-third of those were still entirely self-sufficient. This is good news from both personal and societal perspectives, for it means that exceptional longevity does not necessa
13、rily lead to exceptional levels of disability. Of course, people can live independently without being entirely healthy, and it is true that most centenarians suffer from some sort of ailment. These range from osteoarthritis which is almost universal and often omitted from studies to simple lonelines
14、s. Neurodegenerative (神经退化性 ) diseases are common too, with around 70 to 85 per cent of centenarians suffering from some form of dementia. But dementia in this group follows a different pattern to the general population. It is more likely to be vascular dementia or rare neurodegenerative conditions,
15、 such as Picks disease or Lewy body disease. Alzheimers disease, the most common form of dementia, is relatively rare among centenarians yet, intriguingly; autopsies reveal that the brains of the oldest old, who had shown no outward sign of dementia, are sometimes riddled with the lesions associated
16、 with Alzheimers disease. The basis of this resilience to Alzheimers is largely unknown. The simple fact is that many people who become centenarians seem able to tolerate damage that would significantly harm less robust individuals, and although many suffer from dementia as death draws near, most re
17、main mentally agile well into their nineties. Not all of the oldest old survive by delaying illness or disability, though many soldier through it. Jessica Evert of Ohio State University in Columbus examined the medical histories of over 400 centenarians. She found that those who achieve extreme long
18、evity tend to fall into three categories. About 40 per cent were “delayers“, who avoided chronic diseases until after the age of 80. This “compression of morbidity“, where chronic illness and disability are squeezed into ever-shorter periods at the end of life, is a recent trend among ageing populat
19、ions. Another 40 per cent were “survivors“, who suffered from chronic diseases before the age of 80 but lived longer to tell the tale. The final 20 per cent were “escapers“, who hit their century with no sign of the most common chronic diseases, including heart disease, cancer, diabetes, hypertensio
20、n and stroke. Intriguingly, one-third of male centenarians were in this category, compared with only 15 per cent of women. So what are the secrets of a long and healthy life? Gerontologists (老年医学家 ) point to four key factors: diet, exercise, “psycho-spiritual“ and social, so anyone aiming for a cent
21、ury should not underestimate the power of lifestyle despite the odd centenarian who proudly claims to have smoked 60 cigarettes a day for decades. Thomas Perls, who heads the NECS, believes that up to 70 per cent of longevity is due to non-genetic factors. Nevertheless, many people who live well int
22、o old age do tend to have another advantage: an inherited genetic pass. Take a close relative of a centenarian and you can put good money on their chances of living a long life. Among Americans born in 1900, brothers of centenarians were 17 times as likely to reach a century as their peers, and sist
23、ers, eight times. The New England study reveals that the children of centenarians are less than one-third as likely to die of cancer as the general population, and less than one sixth as likely to die of heart disease. Further evidence of a genetic link comes from longevity hotspots. Okinawa in Japa
24、n is the front runner. At 58 centenarians per 100,000 people, it has the worlds highest proportion in this age group more than five times the level of some developed countries. Like other hotspots, including Sardinia and Iceland, Okinawa is a relatively isolated island community, which leads to high
25、er levels of inbreeding and a clustering of genetic variants. While such genetic similarity usually has detrimental effects, in these hotspots it seems to have united and maintained genetic variants that predispose people to a long life. Of course, members of isolated communities or families usually
26、 share a particular environment too, but this alone cannot explain clusters of longevity. Gerontologists have found that the influence of environmental factors such as wealth or education on lifespan fades as we age, while that of genes increases. By comparing 10,000 pairs of Scandinavian twins, Chr
27、istensen found that genes only start exerting a strong influence on our lifespan after the age of 60. Before then, both identical and non-identical twins have largely independent odds of reaching a given age. Beyond 60, however, the odds of one twin reaching a given age are greatly increased if thei
28、r cotwin has done so, especially if the twins are identical. This makes the “centenarian genome“ a key resource for identifying “longevity genes“, an invaluable step in understanding the physiological processes underlying long lives. Such genes have been found in abundance in other organisms includi
29、ng over 70 in the worm Caenorhabditis elegans (秀丽线虫 ). Unfortunately, its a different story in humans. While many candidate genes have been suggested to affect lifespan, very few have been consistently verified in multiple populations. So far the search for longevity genes in humans has been extreme
30、ly difficult, but prospects brighten as genomic technologies become faster and there are more centenarians to study. Only a lucky few win the genetic lottery of longevity, but if we understand what sets them apart, we may be able to make the rest of us more like them by using lifestyle or therapeuti
31、c interventions to manipulate physiological pathways. Such medical advances will not only extend our lives, but also help us remain healthy and independent for as long as possible. 2 What tendency does the population structure show in many developed countries? （ A） The health condition of the centen
32、arians is degrading. （ B） The younger generations burden becomes heavier. （ C） The social status of the centenarians is rising. （ D） The number of centenarians is increasing rapidly. 3 According to the second paragraph, many people think that the increasing number of the elderly （ A） is good news fo
33、r those who want to live a long life （ B） indicates that peoples living condition has been enhanced greatly （ C） can put great pressure on the society in terms of costs and commitments （ D） will not be accompanied with various chronic diseases 4 What is the physical condition of the average super-ce
34、ntenarians, according to researchers? （ A） They are healthy enough to take care of themselves in daily life. （ B） They constantly suffer a lot from the diseases of aged people. （ C） They are usually free from diseases due to their strong immune systems. （ D） They are so infirm that they need support
35、 from people around them. 5 What does the study conducted in Denmark find? （ A） A number of centenarians are emerging in recent years. （ B） Most people can lead a long life with the right lifestyle. （ C） Disability does not necessarily accompany the oldest people. （ D） All centenarians are faced wit
36、h great risks of developing diseases. 6 What is the recent trend among ageing populations, according to Jessica Evert? （ A） Their health condition is becoming better and better as the society develops. （ B） They only develop chronic illness and become disabled in a short time before they die. （ C） M
37、ore and more of them can escape the attack of most common chronic diseases. （ D） The female centenarians increasingly outnumber the male ones. 7 What is gerontologists advice to people who want to live long? （ A） They should have a healthy lifestyle. （ B） They should visit doctors regularly. （ C） Th
38、ey should keep away from polluted environment. （ D） They should persist in doing exercise every day. 8 What opinion does Thomas Perls express in this passage? （ A） The influence of wealth on lifespan fades as people age. （ B） Most longevity has no relation to genetic factors. （ C） Isolated environme
39、nt can increase the odds of long life. （ D） Centenarians ability to bear diseases is higher than most people. 9 According to the passage, a clustering of genetic variants in Okinawa results from its relative_. 10 _will exert an increasing influence on lifespan as people grow older, according to the
40、passage. 11 Besides the number of available centenarians, the advancement of_will make it possible to find longevity genes in humans. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be as
41、ked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer. （ A） It is a pity that there is a flaw on it. （ B） It is a
42、 good bargain but it could be much cheaper. （ C） It should be showed to some of the womans friends. （ D） It is a real bargain because the flaw is hardly noticeable. （ A） She could play games on the campus net. （ B） The man should go and enjoy the performance. （ C） The man can enjoy the performance w
43、ithout going out. （ D） She would stay at the dormitory and watch the performance. （ A） To talk with Mary about going to the concert. （ B） To ask Mary to stop worrying about the exam. （ C） To help Mary to prepare for the upcoming concert. （ D） To persuade Mary to spend more time on her study. （ A） He
44、 cooks for the club members quite often. （ B） He wasnt careful when he was preparing food. （ C） He often fills the kitchen with tomato and chocolate. （ D） He doesnt like to prepare food for the club members. （ A） Enjoyable. （ B） Inspiring. （ C） Moving. （ D） Dull. （ A） Its too late for the man to fin
45、d a tutor. （ B） She hasnt prepared for the midterm exam either. （ C） The man shouldnt hire the same tutor that she had. （ D） The man should hire a tutor before the midterm exam. （ A） The test was difficult for him. （ B） The test lasted only one hour. （ C） The time is too short for the whole test. （
46、D） The man only finished the first page of the test. （ A） Teachers like Professor Johnson are rare. （ B） Professor Johnson has won a million dollars. （ C） There are many teachers as good as Professor Johnson. （ D） Professor Johnson is likely to be teaching at that school. （ A） To get a library card.
47、 （ B） To get familiar with the resources there. （ C） To borrow some books he needs. （ D） To study how to use the computer to locate the books in the library. （ A） The man used to live in the city. （ B） The library uses computer systems. （ C） The woman is ready to help. （ D） The man is confident of h
48、is computer skills. （ A） A city guide. （ B） A librarian. （ C） A computer expert. （ D） A registrar. （ A） He is conducting a survey. （ B） He is doing a search. （ C） He is trying to improve the Student Union. （ D） He is asking for directions. （ A） It is too small and students sometimes have to stand in
49、 a line. （ B） There are a variety of learning programs for the students. （ C） There are very qualified teachers giving classes on computers. （ D） It is introduced to the students in their first class. （ A） The Computer Center. （ B） The library. （ C） The photocopying facilities. （ D） The lecture rooms. （ A） She is a university staff. （ B） She sometimes drives to the university. （ C） She is very fond of playing computer games. （ D） She is working part time in the library. Section B Directions: In this section
