剑桥雅思6Test3阅读Passage3真题+答案+解析

　　READING PASSAGE 3

　　You should spend abou 20 minutes on Questions 28- -40, which are based on Reading Passage 3below

　　The Search for the Anti-aging Pill

　　In government laboratories ond elsewhere, scientists are seeking a drug able to prolong

　　life and youthful vigor. Studies of caloric restriction are showing the way

　　AS researchers on aging noted recently, no treatment on the market today has been proved toslow human aging - the build-up of molecular and cellular damage that increases vulnerability toinfirmity as we grow older. But one intervention, consumption of a (ow -calorie* yet nutritionallybalanced diet, works incredibly well in a broad range of animals, increasing longevity and

　　prolonging good health. Those findings suggest that caloric restriction could delay aging andincrease longevity in humans, too.

　　Unfortunately, for maximum benefit, people would probably have to reduce their caloric

　　intake by roughly thirty per cent. equivalent to dropping from 2,500 caloriesa day to I,750. Fewmortals could stick to that harsh a regimen, especially for years on end. But what if someonecould create a pill that mimicked the physiological effects of eating less without actually forcingpeople to eat less? Could such a 'caloric-restriction mimetic', as we call it, enable people to stayhealthy longer, postponing age-related disorders (such as diabetes, arteriosclerosis, heart diseaseand Cancer) until very late in lif? Scientists first posed this question in the mid-l 990s, after

　　researchers came upon a chemical agent that in rodencs seemed to reproduce many of caloricrestriction's benefis. No compound that would safely achieve the same feat in people has beenfound yet, but the search has been informative and has fanned hope that caloric-restriction (CR)mimetics can indeed be developed evencually.

　　The benefits of caloric restriction

　　The hunt for CR mimetics grew out of a desire [o better understand caloric restriction's manyeffects on the body. Scientists first recognized the value of the practice more than 60 years ago,when they found that rats fed a low-calorie diet lived longer on average than free-feeding ratsand also had a reduced incidence of conditions that become increasingly common in old age.What is more, some of the treated animals survived longer than the oldest-living animals in thecontrol group, which means chat the maximum lifespan (the oldest attainable age), not merelythe normal lifespan, increased. Various interventions, such as infection-fighting drugs, can

　　increase a population's average survival time, but only approaches that slow the body's rate ofaging will increase the maximum lifespan.

　　The rat findings have been replicated many times and extended co creatures ranging from

　　yeast to fruit flies, worms, fish, spiders, mice and hamsters. Until fairly recently, the scudies werelimited to short-lived creatures genetically distant from humans. But caloric-restriction projectsunderway in two species more closely related to humans - rhesus and squirrel monkeys - havemade scientists optimistic that CR mimetics could help people.

　　* calorie: a measure of the energy value of food

　　阅读3

　　你应该花 20 分钟在问题 28 - - 40， 这是基于阅读通道 3 下

　　寻找抗衰老药丸

　　在其他地方的政府实验室里，科学家们正在寻求一种能够延长

　　生活和青春的活力。热量限制的研究正在被展示

　　正如老龄问题研究人员最近指出的，目前市场上还没有任何治疗方法能够降低人类衰老——随着年龄的增长，分子和细胞损伤的积累增加了对病毒的脆弱性。但一种干预，消费(ow-卡路里*，但营养平衡的饮食)，工作令人难以置信的好，在广泛的动物，增加寿命和

　　延长身体健康。这些发现表明，热量限制可以延缓衰老，延长人类的寿命。

　　不幸的是，为了的利益，人们可能必须减少他们热量

　　摄入量约30%。相当于从每天2，500卡路里下降到1，750卡路里。很少人能坚持这种苛刻的方案， 尤其是多年来。但是，如果有人能够制造出一种药丸，模仿少吃的生理效果，而不强迫人们少吃呢?这种"热量限制的模仿者"，正如我们所说的，能否使人们能保持健康更长的时间，将与年龄相关的疾病(如糖尿病、动脉硬化、心脏病和癌症)推迟到晚的活体?科学家在990年代中期提出这个问题，

　　研究人员发现了一种化学剂，这种剂在马顿身上似乎复制了许多热量的贝内菲斯。目前还没有一种化合物能够安全地在人们中实现同样的壮举，但搜索已经提供了信息，并激起了人们希望热量限制(CR)生物学确实可以发展均匀。

　　热量限制的好处

　　对CR哑剧的寻找源于一种欲望——地了解热量限制对身体的许多影响。科学家在60多年前认识到这种做法的价值，当时他们发现，喂养低热量饮食的老鼠平均寿命比自由喂养的老鼠长，而且发病率也较低，在老年时越来越普遍。更重要的是，一些经过治疗的动物比控制组中最老的动物存活的时间长，这意味着聊天的寿命最长(最老的可达到的年龄)，而不仅仅是正常寿命，增加。各种干预措施，如抗感染药物，可以

　　增加人口的平均生存时间，但只有降低身体寿命的方法才能延长寿命。

　　大鼠的发现已被复制，并扩展共同生物从

　　酵母果蝇，蠕虫，鱼，蜘蛛，老鼠和仓鼠。直到最近，这些潜规则还被限制在基因上远离人类的短命生物身上。但是，两个与人类关系更密切的物种——恒河猴和松鼠猴——的卡路里限制项目，使科学家乐观地认为CR哑剧可以帮助人类。

　　* 卡路里：食物能量值的度量

　　The monkey projects demonstrate that, compared with control animals that eat nomally,caloric-restricted monkeys have lower body temperatures and levels of the pancreatic hormoneinsulin, and they retain more youthful levels of certain hormones that tend to fall with age.

　　The caloric-restricted animals also look better on indicators of risk for age-related diseases.For example, they have lower blood pressure and triglyceride levels (signifying a decreasedlikelihood of heart disease). and they have more normal blood glucose levels (pointing to a

　　reduced risk for diabetes, which is marked by unusually high blood glucose levels). Further, it hasrecently been shown that rhesus monkeys kept on caloric-restricted diets for an extended time(nearly 15 years) have less chronic disease. They and the other monkeys must be followed stilllonger, however, to know whether low-calorie intake can increase both average and maximumlifespans in monkeys. Unlike the multitude of elixirs being touted as the latest anti-aging cure, CRmimetics would alter fundamental processes that underlie aging. We aim如o develop compoundsthat fool cells into activating maintenance and repair.

　　How a prototype caloric-restriction mimetic works

　　The best studied candidate for a caloric-restriction mimetic, 2DG (2-deoxy-D-glucose), worksby interfering with the way cells process glucose. It has proved toxic at some doses in animalsand so cannot be used in humans. But it has demonstrated that chemicals can replicate theeffects of caloric restriction; the trick is finding the right one.

　　Cells use the glucose from food to generate ATP (adenosine triphosphate), the molecule thatpowers many activities in the body. By limiting food intake, caloric restriction minimizes the

　　amount of glucose entering cells and decreases ATP generation. When 2DG is administered oanimals that eat normall, glucose reaches cells in abundance but the drug prevents most of itfrom being processed and thus reduces ATP synthesis. Researchers have proposed several

　　explanations for why interruption of glucose processing and ATP production might retard aging.One possibility relates to the ATP-making machinery's emission of free radicals, which are

　　thought如o contribute to aging and to such age-related diseases as cancer by damaging cells.Reduced operation of the machinery should limit their production and thereby constrain thedamage. Another hypothesis suggests that decreased processing of glucose could indicate tocells that food is scarce (even if it isn't) and induce them to shift into an anti-aging mode thatemphasizes preservation of the organism over such 'luxuries' as growth and reproduction.

　　猴子项目表明，与饮食不全的控制动物相比，受热量限制的猴子的体温和胰腺激素素素水平较低，并且它们保留了更年轻的某些激素水平，这些激素往往随着年龄的增长而下降。

　　热量限制的动物也地寻找与年龄有关的疾病的风险指标。例如，他们的血压和甘油三酯水平较低(表示心脏病的发病率降低)。他们有的正常血糖水平(指向

　　降低患糖尿病的风险，其标志是异常高的血糖水平)。此外，最近还表明，恒河猴长期(近15年)在热量限制下的饮食中患有慢性病较少。然而，他们和其他猴子必须遵循更长期，以知道低热量摄入量是否可以增加平均和生命跨度的猴子。与被吹捧为抗衰老疗法的灵丹妙药不同，CRmimetics 将改变衰老背后的基本过程。我们的目标是开发一种化合物，使细胞能够激活维护和修复。

　　原型热量限制哑剧的工作原理

　　热量限制哑剧的研究候选者，2DG(2-脱氧二-D-葡萄糖)，通过干扰细胞处理葡萄糖的方式。它已被证明在动物的某种剂量有毒，所以不能用于人类。但它已经证明，化学品可以复制热量限制的影响;诀窍是找到正确的。

　　细胞使用食物中的葡萄糖产生ATP(三磷酸腺苷)，这种分子能支持体内的许多活动。通过限制食物摄入量，热量限制限度地减少

　　葡萄糖进入细胞和减少ATP的生成量。当2DG被给药时，吃正常食物的奥体动物，葡萄糖大量到达细胞，但药物防止它大部分被处理，从而减少ATP合成。研究人员提出了几个

　　解释为什么葡萄糖加工和 ATP 生产中断可能会延缓老化。一种可能性涉及ATP制造机械的自由基发射，这是

　　思想有助于衰老和癌症等与年龄相关的疾病，通过破坏细胞。减少机器的运行应限制其生产，从而限制损坏。另一个假设表明，葡萄糖加工的减少可能表明细胞食物稀缺(即使不是)，并促使它们转向一种抗衰老模式，这种模式强调生物体的保全，而不是生长和繁殖等"品"。

　　Questions 28-32

　　Do the following statements agree with the claims of the writer in Reading Passage 3?

　　In boxes 28 -32 on your answer sheet, write

　　YES

　　if the statement agrees with the claims of the writer

　　NO

　　if the statemen1 contradicts the claims of the writer

　　NOT GIVEN

　　if it is impossible 10 say what the writer thinks about this

　　28 Studies show drugs available today can delay the process of growing old.

　　29 There is scientific evidence that eating fewer calories may extend human life.30 Not many people are likely to find a caloric-restricted diet attractive.

　　31 Diet-related diseases are common in older people.

　　32 In experiments, rats who ate what they wanted led shorter lives than rats on a low-

　　calorie diet.

　　Questions 33- -37

　　Classify the ollowing descriptions as relating to

　　A

　　caloric-restricted monkeys

　　control monkeys

　　C

　　neither caloric-restricted monkceys nor control monkeys

　　Write the correct letter; A. B or C, in boxes 33-37 on your answer sheet.

　　33 Monkeys were less likely to become diabetic.

　　34 Monkeys experienced more chronic disease.

　　35 Monkeys have been shown to experience a longer than average life span.36 Monkeys enjoyed a reduced chance of heart disease.

　　37 Monkeys produced greater quantities of insulin.

　　问题28-32

　　下面的陈述与作者在阅读文章3中的主张一致吗?

　　在答题纸上的28-32框中写上

　　是

　　如果陈述与作者的主张一致

　　不

　　如果政治家们反驳了作者的主张

　　不给出

　　如果这是不可能的10说作者的想法

　　28研究表明，今天可用的药物可以延缓衰老的过程。

　　29有科学证据表明，少吃卡路里可能延长人的寿命。30并不是人都认为低热量饮食有吸引力。

　　31与饮食有关的疾病在老年人中很常见。

　　在实验中，想吃什么就吃什么的老鼠比低血糖的老鼠寿命更短。

　　热量饮食。

　　第33题——第37题

　　将描述分类为有关

　　A

　　热量限制的猴子

　　控制猴子

　　C

　　既不限制热量的和尚，也不控制猴子

　　在答题纸上的33-37框中写出正确的字母A.B或C。

　　33只猴子患糖尿病的可能性较小。

　　34只猴子经历了的慢性疾病。

　　35猴子的寿命比平均寿命长。36猴子患心脏病的几率较低。

　　37猴子分泌的胰岛素。

　　Questions 38-40

　　Complete the flow-chart below.

　　Choose NO MORE THAN TWO WORDS from the passage for each answer.

　　Write your answers in boxes 38-40 on your answer sheet.

　　How a caloric-restriction mimetic works

　　CR mimetic

　　Less 38..............is processed

　　Production of ATP is decreased

　　Theory 1: Theory 2:

　　Cells less damaged by disease because Cells focus on 40..............because

　　fewer 39..............are emitted food is in short supply

　　问题38-40

　　完成下面的流程图。

　　从文章中每一个答案选两个单词。

　　将答案写在答题纸上的38-40框中。

　　热量限制模仿者是如何工作的

　　氯丁橡胶模拟物

　　少了38.......被处理了

　　减少ATP的产生

　　理论1：理论2：

　　因为细胞集中在40...因为。..因为。..因为。..被疾病损伤的细胞较少。..因为。..

　　更少的39.......都是排放的食物供不应求

　　剑桥雅思6Test3Passage3答案解析

　　Question 28

　　答案： NO

　　关键词：drugs available today/ growing old

　　定位原文: 第1段第1句“As researchers on aging…”

　　解题思路: 衰老问题的研究者们最近指出，目前市面上还没有任何疗法证明可以延缓人类衰老。“任何疗法”包含药物，所以“目前没有疗法能延缓衰老”就意味着目前没有药物可以延缓衰老。

　　Question 29

　　答案：YES

　　关键词： eating fewer calories/ extend human life

　　定位原文: 第1段最后1句“Those findings suggest…”

　　解题思路: 这些研究结果表明，限制热量的摄取可能也会延缓衰老，延长人类寿命。” scientific evidence与findings是近义词，所以符合题干。

　　Question 30

　　答案：YES

　　关键词： caloric-restricted

　　定位原文: 第2段第2句“Few mortals could…”

　　解题思路: 很少有人能够坚持这样严格的养生之道，喜欢的才能坚持，既然不能坚持，肯定是觉得不够attractive。

　　Question 31

　　答案：NOT GIVEN

　　关键词：diet-related diseases

　　定位原文: 无定位原文

　　解题思路: 原文没有提到这个信息，所以是NOT GIVEN。

　　Question 32

　　答案：YES

　　关键词：rats

　　定位原文: 第3段第2句“… rats fed a low-calorie diet lived…”

　　解题思路: 被喂食低热量食物的鼠类平均寿命长于自由摄取食物的鼠类”，这里关键是知道free-feeding与ate what they wanted是同义表达。

　　Question 33

　　答案：A

　　关键词： less likely / diabetic

　　定位原文: 第6段第2句“...they have more normal blood…( pointing to a reduced risk for diabetes)” 血糖浓度也比较正常(表示得糖尿病的风险较低)。

　　解题思路: 这句话阐述的是calorie-restricted animal的情况，也就是calorie- restricted monkeys的情况，所以正确答案是A。

　　Question 34

　　答案：B

　　关键词：more chronic disease

　　定位原文: 第6段第3句“Further, it has recently…”

　　解题思路: 此外，有关研究最近指出，长期限制热量摄人(将近15年)的恒河猴患慢性病的几率也较低。rhesus monkeys与control monkeys 比较，前者患慢性病几率低，也就是说后者患慢性病几率高。正确答案是B。

　　Question 35

　　答案： C

　　关键词：a longer than average lifespan

　　定位原文: 第6段第4句: “They and other monkeys…” 但想要知道限制热量摄人是否会延长猴类的平均寿命和寿命，我们还必须对这些恒河猴以及其他猴类做更长时间的跟踪研究。

　　解题思路: They 指的是calorie-restricted mon?keys s other monkeys指的就是 control monkeys，原文既然说还需研究才能知道它们的寿命是否得到延长，也就是说两类猴都还没有表明寿命得到延长。正确答案是C。

　　Question 36

　　答案： A

　　关键词：reduced chance of heart disease

　　定位原文: 第6段第2句“For example, they have lower blood pressure and triglyceride levels (signifying a decreased likelihood of heart disease )…” 例如，它们的血压与甘油三酸酯含量都比较低(表示得心脏病的可能性较小)。

　　解题思路: 这句话阐述的是calorie-restricted animal的情况，也就是calorie- restricted monkeys的情况，所以正确答案是A。

　　Question 37

　　答案： B

　　关键词：greater quantities of insulin

　　定位原文: 第5段(就1句话)“..compared with control animals that eat normally, caloric-restricted monkeys have lower body temperatures and levels of the pancreatic hormone insulin.”比起正常饮食的对照组动物，限制热量摄人组猴子的体温和胰岛素浓度都较低。

　　解题思路: 限制热量摄入组的猴子比对照组猴子的胰岛素浓度低，说明其胰岛素分泌量少，故对照组的胰岛素分泌较多。正确答案是B。

　　Question 38

　　答案：glucose

　　关键词：production of ATP is decreased

　　定位原文: 第8段第2句“By limiting food intake, caloric restriction…” 通过限制食物的摄取量，可使进入细胞的葡萄糖降到，因此减少ATP的生成量。

　　解题思路: 通过 minimizes the amount of glucose 和 less … is processed 的同义转换关系很快选出答案应该是glucose。

　　Question 39

　　答案： free radicals

　　关键词：one possibility

　　定位原文: 第8段第5句“One possibility relates to the ATP-making…” 其中一种说法与ATP生成过程中自由基的释放有关，人们认为自由基会损伤细胞，因此引起衰老以及像癌症这类与衰老有关的疾病。

　　解题思路: 根据原文，free radicals促进 cancer之类的disease破坏细胞，所以free radicals越少，被疾病破坏的细胞就越少。即题目中给出的部分：cells less damaged by disease，所以答案为free radicals。

　　Question 40

　　答案： preservation

　　关键词： focus on

　　定位原文: 第8段最后1句“Another hypothesis suggests…” 另一种假设认为，葡萄糖代谢的降低让细胞以为食物不足(即使事实并非如此)，而促使细胞进人抗衰老的状态，这种状态着重的是维持……

　　解题思路: emphasize与focus on属于同义表达，scarce与in short supply属于同义表达，所以对应答案为preservation。