1、大学英语六级改革适用（阅读）模拟试卷 258及答案与解析 Section C 0 Most growing plants contain much more water than all other materials combined. C. R. Barnes has suggested that it is as proper to term the plant a water structure as to call a house composed mainly of brick a brick building. Certain it is that all essential p
2、rocesses of plant growth and development occur in water. The mineral elements from the soil that are usable by the plant must be dissolved in the soil solution before they can be taken into the root. They are carried to all parts of the growing plant and are built into essential plant materials whil
3、e in a dissolved state. The carbon dioxide (CO2) from the air may enter the leaf as a gas but is dissolved in water in the leaf before it is combined with a part of the water to form simple sugars the base material from which the plant body is mainly built Actively growing plant parts are generally
4、75 to 90 percent water. Structural parts of plants, such as woody stems no longer actively growing, may have much less water than growing tissues. The actual amount of water in the plant at any one time, however, is only a very small part of what passes through it during its development. The process
5、es of photosynthesis, by which carbon dioxide and water are combined in the presence of chlorophyll (叶绿素 ) and with energy derived from light to form sugars, require that carbon dioxide from the air enter the plant. This occurs mainly in the leaves. The leaf surface is not solid but contains great n
6、umbers of minute openings, through which the carbon dioxide enters. The same structure that permits the one gas to enter the leaf, however, permits another gas water vapor to be lost from it. Since carbon dioxide is present in the air only in trace quantities (3 to 4 parts in 10,000 parts of air) an
7、d water vapor is near saturation in the air spaces within the leaf (at 80F, saturated air would contain about 186 parts of water vapor in 10,000 parts of air), the total amount of water vapor lost is many times the carbon dioxide intake. Actually, because of wind and other factors, the loss of water
8、 in proportion to carbon dioxide intake may be even greater than the relative concentrations of the two gases. Also, not all of the carbon dioxide that enters the leaf is synthesized into carbohydrates (碳水化合物 ). 1 A growing plant needs water for all of the following except_. （ A） forming sugars （ B）
9、 sustaining woody stems （ C） keeping green （ D） producing carbon dioxide 2 The essential function of photosynthesis in terms of plant needs is _. （ A） to form sugars （ B） to derive energy from light （ C） to preserve water （ D） to combine carbon dioxide with water 3 The second paragraph uses facts to
10、 develop the essential idea that _. （ A） a plant efficiently utilizes most of the water it absorbs （ B） carbon dioxide is the essential substance needed for plant development （ C） a plant needs more water than is found in its composition （ D） the stronger the wind, the more the water vapor loss 4 Fr
11、om the passage, we learn that_. （ A） the mineral elements will not be absorbed by the plant unless they are dissolved in its root （ B） the woody stems contain more water than the leaves （ C） air existing around the leaf is found to be saturated （ D） only part of the carbon dioxide in the plants is s
12、ynthesized 5 This passage is mainly about_. （ A） the functions of carbon dioxide and water （ B） the role of water in a growing plant （ C） the process of simple sugar formation （ D） the synthesis of water with carbon dioxide 5 Birds that are literally half-asleep with one brain hemisphere alert and t
13、he other sleeping control which side of the brain remains awake, according to a new study of sleeping ducks. Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled
14、by the sleeping hemisphere keeps shut, while the wakeful hemispheres eye stays open and alert. Birds also can sleep with both hemispheres resting at once. Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the-row sleepers. Sure enough, the en
15、d birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction. Also, birds dozing (打盹 ) at the end of the line resorted to single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16
16、birds through the positions in a four-duck row, the researchers found outer birds half-asleep during some 32 percent of dozing time versus about 12 percent for birds in internal spots. “We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously
17、in different regions of the brain,“ the researchers say. The results provide the best evidence for a long-standing supposition that single-hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. Hes seen it in
18、 a pair of birds dozing side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open. Useful as half-sleeping might be, its only been found in birds and such water mammals (哺乳动物 ) as dolphins, wh
19、ales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning. Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds half-brain sleep “is just the tip of the iceberg (冰山 ).“ He sp
20、eculates that more examples may turn up when we take a closer look at other species. 6 A new study on birds sleep has revealed that _. （ A） half-brain sleep is found in a wide variety of birds （ B） half-brain sleep is characterized by slow brain waves （ C） birds can control their half-brain sleep co
21、nsciously （ D） birds seldom sleep with the whole of their brain at rest 7 According to the passage, birds often half sleep because _. （ A） they have to watch out for possible attacks （ B） their brain hemispheres take turns to rest （ C） the two halves of their brain are differently structured （ D） th
22、ey have to constantly keep an eye on their companions 8 The example of a bird sleeping in front of a mirror indicates that _. （ A） the phenomenon of birds dozing in pairs is widespread （ B） birds prefer to sleep in pairs for the sake of security （ C） even an imagined companion gives the bird a sense
23、 of security （ D） a single pet bird enjoys seeing its own reflection in the mirror 9 While sleeping, some water mammals tend to keep half awake in order to _. （ A） alert themselves to the approaching enemy （ B） emerge from water now and then to breathe （ C） be sensitive to the ever-changing environm
24、ent （ D） avoid being swept away by rapid currents 10 By “just the tip of the iceberg“ (Line 2, Para. 8), Siegel suggests that_. （ A） half-brain sleep has something to do with icy weather （ B） the mystery of half-brain sleep is close to being solved （ C） most birds living in cold regions tend to be h
25、alf sleepers （ D） half-brain sleep is a phenomenon that could exist among other species 10 The destruction of our natural resources and contamination of our food supply continue to occur, largely because of the extreme difficulty in affixing (把 固定 ) legal responsibility on those who continue to trea
26、t our environment with reckless abandon. Attempts to prevent pollution by legislation, economic incentives and friendly persuasion have been met by lawsuits, personal and industrial denial and long delays not only in accepting responsibility, but more importantly, in doing something about it. It see
27、ms that only when government decides it can afford tax incentives or production sacrifices is there any initiative for change. Where is industrys and our recognition that protecting mankinds great treasure is the single most important responsibility? If ever there will be time for environmental heal
28、th professionals to come to the frontlines and provide leadership to solve environmental problems, that time is now. We are being asked, and, in fact, the public is demanding that we take positive action. It is our responsibility as professionals in environmental health to make the difference. Yes,
29、the ecologists, the environmental activists and the conservationists serve to communicate, stimulate thinking and promote behavioral change. However, it is those of us who are paid to make the decisions to develop, improve and enforce environmental standards, I submit, who must lead the charge. We m
30、ust recognize that environmental health issues do not stop at city limits, county lines, state or even federal boundaries. We can no longer afford to be tunnel-visioned in our approach. We must visualize issues from every perspective to make the objective decisions. We must express our views clearly
31、 to prevent media distortion and public confusion. I believe we have a three-part mission for the present. First, we must continue to press for improvements in the quality of life that people can make for themselves. Second, we must investigate and understand the link between environment and health.
32、 Third, we must be able to communicate technical information in a form that citizens can understand. If we can accomplish these three goals in this decade, maybe we can finally stop environmental degradation, and not merely hold it back. We will then be able to spend pollution dollars truly on preve
33、ntion rather than on bandages. 11 We can infer from the first two paragraphs that the industrialists disregard environmental protection chiefly because _. （ A） they are unaware of the consequences of what they are doing （ B） they are reluctant to sacrifice their own economic interests （ C） time has
34、not yet come for them to put due emphasis on it （ D） it is difficult for them to take effective measures 12 The main task now facing ecologists, environmental activists and conservationists is _. （ A） to prevent pollution by legislation, economic incentives and persuasion （ B） to arouse public aware
35、ness of the importance of environmental protection （ C） to take radical measures to control environmental pollution （ D） to improve the quality of life by enforcing environmental standards 13 The word “tunnel-visioned“ (Line 2, Para. 4) most probably means “_“. （ A） narrow-minded （ B） blind to the f
36、acts （ C） short-sighted （ D） able to see only one aspect 14 According to the author, what should play the leading role in the solution of environmental problems? （ A） Legislation and government intervention. （ B） The industrys understanding and support. （ C） The efforts of environmental health profe
37、ssionals. （ D） The cooperation of ecologists, environmental activists and conservationists. 15 According to the last paragraph, we learn that _. （ A） efforts should be exerted on pollution prevention instead of on remedial measures （ B） more money should be spent in order to stop pollution （ C） ordi
38、nary citizens have no access to technical information on pollution （ D） environmental degradation will be stopped by the end of this decade 大学英语六级改革适用（阅读）模拟试卷 258答案与解析 Section C 【知识模块】 仔细阅读 1 【正确答案】 D 【试题解析】 文章谈到的二氧化碳都是空气中的二氧化碳，不是植物 “产生的二氧化碳 ”，故可知 D项符合题意。 A、 B、 C项都是植物的生长发育过程。尽管 C项并没有在文中明言，但它也是植物内水分的
39、作用之一。 【知识模块】 仔细阅读 2 【正确答案】 A 【试题解析】 根据第 2段第 2句可知，光合作用的主要作用是利用叶绿素，在光能的作用下，把二氧化碳和水结合形成糖。由此可以归纳光合作用的最终目的是生产植物所需的糖， A符合题意。 B项和 D项都是光合作用发生的条件而非目的。 【知识模块】 仔细阅读 3 【正确答案】 C 【试题解析】 从第 2段的首句 “植物在任何特定时期的含水量都只是其生长过程中流经植物的水总量的一小部分 ”可以判断 C符合题意。其他三个选项也都符合原文意思，但都不是第二段的分话题。 【知识模块】 仔细阅读 4 【正确答案】 D 【试题解析】 第 2段最后一句话明确指
40、出，并非所有进入植物叶片的二氧化碳都与水化合成为碳水化合物。故 D正确。 A与第 1段第 4句不符，即矿物质需溶解在土壤溶液 (soil solution)中而非植物的根部 (root)； C在倒数第 3句可以找到反证，即水蒸气在叶片空隙中接近饱和状态，而非如 C项所说 “在叶片周围呈饱和状态 ”； B在文中未提及。 【知识模块】 仔细阅读 5 【正确答案】 B 【试题解析】 从本文主题来看，应当是水在植物生长过程中的重要性， B最符合题意。本文第二段花许多篇幅介绍了光合 作用，其目的还是为了说明水的作用。A、 C、 D项偏重于讲光合作用，并非全文主题。 【知识模块】 仔细阅读 【知识模块】
41、仔细阅读 6 【正确答案】 C 【试题解析】 第 1段提到 “根据对睡鸭的一项新研究，那些真正进行半脑睡眠的鸟类 它们半个大脑警醒，半个大脑沉睡 控制着让哪一半大脑保持清醒 ”，也就是说能自觉地控制大脑的状况， C正确。 A和 B是早期研究的结果； D与文章的意思不符。 【知识模块】 仔细阅读 7 【正确答案】 A 【试题解析】 第 6段首句提到 “新的研究成果为长期 以来的一种设想提供了最好的证据，即半脑睡眠机制是动物为防范敌人进化而来的 ”， A与文章观点一致； B只是讲述了半脑睡眠是怎么回事，并没有告知原因； C文中没有提及； D与文中内容不符。 【知识模块】 仔细阅读 8 【正确答案】
42、 C 【试题解析】 第 6段最后两句提到 “研究者看见一只鸟儿靠着镜子睡觉。那只鸟对着镜子的那只眼睛是闭着的，仿佛镜中的影像是它的同伴。而它的另外一只眼则是睁开的 ”， C与此一致。 A和 B中的 in pairs是对原文的误读；鸟儿喜欢结群(而不一定是成双成对 )睡眠，文章前几段对此有说明。 D中的 enjoy属于无中生有。 【知识模块】 仔细阅读 9 【正确答案】 B 【试题解析】 第 7段末句提到 “也许一边大脑保持清醒是为了让睡眠中的动物不时浮出水面以免被淹死 ”， B与文中所提及的观点一致。 【知识模块】 仔细阅读 10 【正确答案】 D 【试题解析】 最后一段提到 “Siegel说
43、他想知道鸟类的半脑睡眠机制是否 只是冰山浮出水面的那一角 ，并推测当我们进一步研究其他物种时可能还会发现更多的例子 ”， D与文中所述相符。 A文中没有提及； B、 C与文意不符。 【知识模块 】 仔细阅读 【知识模块】 仔细阅读 11 【正确答案】 B 【试题解析】 根据第 1段末句 “个人和企业拒绝和长期拖延在防治污染方面承担责任或采取行动 ”和第 2段首句 “似乎只有政府下决心提供税收优惠政策或牺牲生产，情况才会开始有所改变 ”，可知企业忽视环境保护主要出于经济效益的考虑，B正确。 A、 C与文中所陈述之意相悖； D文中没有提及。 【知识模块】 仔细阅读 12 【正确答案】 B 【试题解
44、析】 第 3段第 3句提到：生态学者、环境保护积极分子和环境保护论者应积极与人们交流思想，激起人 们思考环境问题，并促进人们的行为发生变化，由此可知 B正确。 A、 C都不是他们的任务； D文中没有提及。 【知识模块】 仔细阅读 13 【正确答案】 D 【试题解析】 考查的生词是 tunnel“隧道 ”和 vision“洞察力，视力 ”的合成词。结合文章第 4段：在方法上，我们再也不能 tunnel-visioned，我们必须从各个方面对待问题，并做出客观的决定。由此可知 tunnel-visioned是 “从各个方面看问题的 ”反义词。再结合字面意思，可猜测该词意为 “片面地看问题 ”， D
45、正确。 【知识模块】 仔细阅读 14 【正确答案】 C 【试题解析】 第 2段第 3句提到：环保专业人员走在前头，在解决环境问题中起领导作用的时机已经到来。第 3段最后一句又指出：我们这些拿薪水为环保工作的发展、提高出谋划策并执行环境标准的人必须承担起领头的责任。因此， C正确。其他三项均不是起关键作用的因素。 【知识模块】 仔细阅读 15 【正确答案】 A 【试题解析】 文章最后一句提到：如果这 10年我们能实现这三个目标，也许最终我们能阻止而不是暂时抑制环境的恶化。那么我们也就不用采取补救措施，而且能将治理 污染的费用真正用于保护环境。 bandage原义为 “绷带 ”，这里取比喻义，意为 “治疗，补救 ”。 A正确； B文中没有提及； C、 D与文意相悖。 【知识模块】 仔细阅读
