2002年考研英语阅读解析

这一篇小文，小编就给大家解析一下2000年~2004年考研英语的五篇作文，帮助大家更好地把握考研英语的写作思路和选题走向。#考研英语#2000年真题作文部分2000年这一年考察的是图画作文。自图画作文登场，考研英语作文从形式上看的几大类型文章基本都出现了。这一年的作文给出了两张图片，图片下面有一句话，指明了方向。作文的字数要求是不少于150词。除此以外，题目中还给出了文章的内容提纲。文章的话题是：“过度捕捞”；标题自拟；主题词是“over-fishing”。文章结构大体可以分为三段：其一是“描述图画”，阐明两幅图的不同即变化，其二是“总结图画所反映的现象”，其三是“给出合理的解决建议”。作文分值15分。So it is high time we took effective measures to solve this problem.所以，我们是时候采取一些有效的措施去解决这一问题了。2001年真题作文部分2001年这一年考察的也是图画作文。有的老师也称之为“漫画作文”，其实都是可以的。这篇文章从题干来看，和之前的漫画作文有了很大的变化，这些变化体现为：其一，作文的分值从15分变成了20分；其二，在题干的开头给出了一段描述，显然是在提示文章的主题；其三，字数要求由原来的的150词变成了200词。当然，文章给出了写作的思路：第一段是对漫画的描述，解释考生对漫画后文章象征意义的了解；第二段是给出一个具体的例子，来论证观点；第三段是给出相关的献爱心的建议。文章的话题是“爱心”；主题词是“love”。There is probably no other feeling that is nobler than love. Everybody not only needs love ，but also should give others love.大概没有一种感觉比爱更高贵了。每个人都不仅需要爱，更应该把爱传递给别人。2002年真题作文部分2002年这一年考察的是图画作文。但是和以前不同，不是漫画，而是一张穿着中国传统服装的美国女孩的照片。从题干来看，和去年漫画作文的要求是一致的。首先是给出了一段描述，但是这里的描述意义不大；其次是交代考生文章的内容要求；接下来是作文的字数要求和分值：作文的分值为20分，字数要求为200词。这篇文章可以分成三部分来写：第一段是对照片的描述，这题相对简单，因为题干和照片下方已经给出了相应的语料；第二段是解释图片背后的含义，要注意，服装只是表现，其“里”指的应该是“文化”的内容；第三段是给出考生自己的观点、评论或者是建议，当然指的应该是文化输出的建议，因为这毕竟是一个美国女孩。文章的话题是“文化交流”；主题词是“cultural exchange”；分值是20分。All in all，cultural exchange is an effective way to achieve efficient cross-cultural communication and promote world peace and prosperity.总之，文化交流是一种有效的实现跨文化交流和促进世界和平和繁荣的方式。2003年真题作文部分2003年这一年考察的是漫画作文。题干可以说是越来越精简，可以说题干中有效的信息就是思路和词数、分值的说明。字数要求是200词左右；分值是20分；文章的话题可以理解为“儿童教育”，也可以理解为“挫折的重要性”；主题词是“hardship/difficulties”。行文的结构应该是三段：第一段是对图表的内容进行简单描述，重点揭示前后的变化；第二段是揭示漫画在现实中的含义，也可以写一写“温室”对于“花朵”究竟会有怎样的危害；第三段是给出看法和建议，或者是呼吁也可。Thus，it is high time that parents，ecatiors and the government made joint efforts put an end to this situation.因此，家长、教育者、政府是时候共同努力来结束这样的情况了。2004年真题作文部分2004年这一年考察的是漫画作文。题干中的有效信息是思路，其余和去年没有任何变化。字数要求是200词左右；分值是20分；文章的话题是“终点和起点”；主题词是“final spur and starting point”。文章的写作思路是：第一段对漫画的内容进行描述，第二段指出这图画含义的社会现状，第三段提出支撑自己观点的例子，比如大学生毕业，既是一个阶段的结束，有时一个新阶段的开始。Only when we are well-prepared for it can we meet the challenge in the future.我们只有做好准备才能迎接未来的挑战。考研英语是很难的好了，这就是2000年~2004年考研英语作文的全部解析，很是很走心的喽，如果帮助到了你，感谢点赞关注哈~（真题图书推荐陈正康老师的《真题超精读》，很详细，也很走心~不过要注意自己考得究竟是一还是二，千万不要买错了喽）政治：“对国家出路的早期探索”专题易错考点考研英语：1994~1999年真题作文全解析

想必很多同学都听过考研英语阅读的文章大都是摘自外国的学术期刊或者报纸那，具体是哪些外刊?应该选择哪些中奖概率比较高呢?来，我们先从20年英语一的文章来源开说↓(20考研英语二的题源我在网上还没搜到，哭唧唧)阅读理解首篇选自：《卫报》2018年12月31日文章《The Guardian view on Yvette Cooper’s ‘town of culture’proposai：a fine idea》第二篇选自：《卫报》2019年3月5日文章《The Guardian view on academic publishing：disastrous capitalism》第三篇选自：《波士顿环球报》2019年8月5日文章《Corporate gender quotas reinforce privilege》第四篇选自：《纽约日报》2019年7月15日文章《Beware.Other Nations Will Follow France With Their Own Digital Tax》由上可见，卫报的出场率很高，但仅从20年的数据我们不能就此下定论下面再来看一份2015-2019年真题文章的来源统计英语一英语二在上面这份英语一、二年15-20考研阅读真题阅读文章来源总结中不难看出《卫报》《经济学人》《基督教箴言》出场率极高像《时代周刊》《自然杂志》、《新闻周刊》、《科学美国人》也有不少分布。其他则包括有：《新科学家》、《社评杂志》、《福布斯》、《哈佛经济评价》、《麦肯锡季刊》、《科学探索》、《科学》、《观察家报》、《哈佛杂志》、《美国学校董事会杂志》、《星报在线》、《Big Think》、《华盛顿邮报》近两年《基督教科学箴言报》上镜率有提高，可以多关注下。我们再就以上数据做个总结1、 经济类文章主要来源：The Economist (经济学人)，Business Week (商业周刊)，Wall Street Journal(华尔街杂志);2、 科学技术类文章主要来源：Nature (自然)，Discovery (探索)，Science (科学)，National Geographic (国家地理)，Scientific American (科学美国人)，New Scientists (新科学家);3、 社会生活以及文化类文章主要来源：Newsweek (新闻周刊)，Times (时代周刊)，U.S News and World Report (美国新闻与世界报道)，The Washington Post (华盛顿邮报)，USA Today (今日美国)，The Times (泰晤士报)，The Guardian (卫报);4、 其它来源：Independent (独立日报)， International New York Times(国际纽约时报)， Telegraph (英国电信日报)。

It is all very well to blame traffic jams, the cost of petrol and the quick pace of modern life, but manners on the roads are becoming horrible. 我们可以谴责交通阻塞、汽油价格、以及现代生活的快节奏，但马路礼貌确实越来越糟糕。Everybody knows that the nicest men become monsters behind the wheel. It is very well, again, to have a tiger in the tank, but to have one in the driver’s seat is another matter altogether.所有的人都知道：即便脾气最好的人在车里也会变成怪兽。老虎在油箱里还好说，可老虎若坐在驾驶员的位置上就完全是另一回事了。You might tolerate the odd road-hog, the rude and inconsiderate driver, but nowadays the well-mannered motoristis the exception to the rule. Perhaps the situation calls for a “Be Kind to Other Drivers” campaign, otherwise it may get completely out of hand.你也许能够容忍在马路上横冲直闯的司机、粗鲁且不体谅人的司机，但现今文明驾驶的司机却实属罕见。(可能这需要发起一场“对其他司机友善”的运动，否则，情形会完全失控)。第二段：Road politeness is not only good manners, but good sense too. It takes the most cool-headed and good-tempered of drivers to resist the temptation to revenge when subjected to uncivilized behavior.马路文明不仅是一种礼貌行为，还是一种良好的意识。司机需要非常冷静的头脑和好脾气才能在碰到不文明行为时克制住自己不进行报复。On the other hand, a little politeness goes a long way towards relieving the tensions of motoring.另一方面，些许文明行为十分有助于缓解驾车时的紧张情绪。A friendly nod or a wave of acknowledgement in response to an act of politeness helps to create an atmosphere of goodwill and tolerance so necessary in modern traffic conditions.一个友好的颔首、感谢对方礼貌行为的一个轻轻的挥手有助于形成友好宽容的氛围，But such acknowledgements of politeness are all too rare today. Many drivers nowadays don’t even seem able to recognize politeness when they see it.而这在当前的交通条件下是非常必要的。但现在，这种对礼貌表示认可的行为非常罕见。现今很多司机即使见到礼貌行为也似乎视若惘然。第三段：However, misplaced politeness can also be dangerous. Typical examples are the driver who brakes violently to allow a car to emerge from a side street at some hazard to following traffic, when a few seconds later the road would be clear anyway;但是，误用礼貌同样危险。典型的事例为：司机为了让过从边路上突然出现的车而采取急刹车，却对后面的交通造成了危险。（而若不出现这种情况），本来只需几秒钟的等待，道路就会畅通无阻；or the man who waves a child across a zebra crossing into the path of oncoming vehicles that may be unable to stop in time. The same goes for encouraging old ladies to cross the road wherever and whenever they care to.或者，有人会为一个穿过斑马线的孩子让路，示意其进入行车道，但随后驶来的车辆却无法及时停车。同样，鼓励老太太随时随地横穿马路的行为也是如此。It always amazes me that the highways are not covered with the dead bodies of these grannies.我经常感到奇怪：高速公路上居然没有屡屡出现这些老太太被撞死的交通事故。第四段：A veteran driver, whose manners are faultless, told me it would help if motorists learnt to filter correctly into traffic streams one at a time without causing the total blockages that give rise to bad temper.一位行为无可挑剔的老司机曾告诉我：在不引起交通阻塞，从而惹怒其他司机的前提下，司机们学会逐个插入车流有助于缓解交通。Unfortunately, modern motorists can’t even learn to drive, let alone master the subtler aspects of boatmanship.但现代的驾驶员甚至不会学如何驾车，更别说掌握公路驾车技能的微妙之处了。Years ago the experts warned us that the car-ownership explosion would demand a lot more give-and-take from all road users. It is high time for all of us to take this message to heart.多年前专家就曾警告我们：汽车拥有量的突增要求所有马路使用者的互谅互让。现在是我们该把这项警告铭记于心的时候了。14. According to this passage, troubles on the road are primarily caused by.[A] people’s attitude towards the road-hog[B] the rhythm of modern life[C] the behavior of the driver[D] traffic conditions[分析] 本题考核知识点：第一段主旨题。第一段第二句至段末的内容指出：好人一旦驾车也可能成为伤人的妖怪；过分大胆的司机（tiger）会造成很大的麻烦；鉴于文明驾车的司机太少的现状，为了不至于情况完全失控，有必要发起名为“对其他司机好点”的运动。这说明，形成道路问题的主要原因是司机的行为。 另外，本文其余部分全部是围绕“司机如何正确运用礼貌（politeness），以减少道路问题”进行讨论。所以，[C]为正确选项。误选[A]是因为没有正确理解You might tolerate…rule，本句旨在说明：文明驾驶的司机并不常见；而并非说明人们对于鲁莽司机的态度。[B]、 [D]舍本逐末：文章第一段提到现代生活的节奏和交通状况是为了引出道路问题的主要原因──司机的行为。15. The sentence “You might tolerate the odd road-hog... the rule.” (Para. 1) implies that.[A] our society is unjust towards well-mannered motorists[B] rude drivers can be met only occasionally[C] the well-mannered motorist cannot tolerate the road-hog[D] nowadays impolite drivers constitute the majority of motorists[分析] 本题考核知识点：根据上下文理解句意。本句大意：你可以容忍古怪、粗鲁、不体谅人的司机，但现今文明驾驶的司机却实属罕见。exception to the rule 意为“例外”。[D] 是the well-mannered motorist is the exception to the rule的改写，表达相同的意思，所以为正确选项。[B]与事实相反。[A]、[C]文中未提及。16. By “good sense,” the writer means.[A] the driver’s ability to understand and react reasonably[B] the driver’s prompt response to difficult and severe conditions[C] the driver’s tolerance of rude or even savage behavior[D] the driver’s acknowledgement of politeness and regulations[分析] 本题考核知识点：根据上下文理解短语。根据题干关键词good sense锁定第二段第一句。由于该句是段落主题句，所以对它的理解必然基于对本段内容的把握。本段第一句指出：马路文明不仅是good manners，还是good sense。下文开始对good sense进行具体阐述。第二句说明如何对待他人不礼貌的行为：克制住自己不进行报复；第三句到段末说明如何对待他人的礼貌行为：表示理解并做出认可的反应。所以，[A]是这两方面内容的概括。[C]和[D]都只涉及一个方面的内容，不全面，[B]中“困难且严峻的条件”太笼统，“快速反应”在该段也没有提到。17. Experts have long pointed out that in the face of car-ownership explosion,.[A] road users should make more sacrifice[B] drivers should be ready to yield to each other[C] drivers should have more communication among themselves[D] drivers will suffer great loss if they pay no respect to others[分析]：本题考核知识点：细节题。根据题干中出现的关键词Experts，car-ownership explosion锁定全文倒数第二句。对本题进行判断的主要依据来自于对短语give-and-take 的理解。考生根据本合成词的构成很容易猜测出give-and-take 意为：互相让步,互相迁就（make mutual concessions），[B]中的yield to each other即为此意，所以为正确选项。18. In the writer’s opinion,.[A] strict traffic regulations are badly needed[B] drivers should apply road politeness properly[C] rude drivers should be punished[D] drivers should avoid traffic jams[分析] 本题考核知识点：作者观点题。理解作者的观点需要纵观全文。本文第二段说明司机应该礼貌驾驶并对同行的礼貌行为做出合理反应。第三段说明司机误用礼貌(misplaced politeness ) 同样危险。所以，本文是从正反两方面分析了politeness对减少道路问题的作用。properly对于作者的观点最具有概括力，所以[B]为正确选项。本文并没有从利用交通法规减少交通问题方面进行讨论，所以[A]非本文论述内容。本文也没有提及对野蛮司机的惩罚，所以[C]非正确选项。文章只在开头作为马路问题产生原因之一提及traffic jam，而并没有提到司机应该避免交通高峰以减少交通问题，所以[D]非正确选项。

原文+翻译：It’s a rough world out there.外面是一个危险的世界。Step outside and you could break a leg slipping on your doormat.迈出家门时，你可能会滑倒在门垫上，而摔伤一条腿。Light up the stove and you could burn down the house.点燃炉灶时，你可能会把房子烧掉。Luckily, if the doormat or stove failed to warn of coming disaster, a successful lawsuit might compensate you for your troubles.不过还算幸运的是，如果门垫或炉灶上没有警示语提醒你可能发生的危险，那么一场成功的诉讼或许可以补偿你所受的伤害。Or so the thinking has gone since the early 1980s, when juries began holding more companies liable for their customers’ misfortunes.这种想法大约自20世纪80年代初开始传播，那时陪审团开始认为更多的公司应对其客户所遭受的不幸负责。Feeling threatened, companies responded by writing ever-longer warning labels, trying to anticipate every possible accident.由于感到了威胁，公司方面做出了反应：写出越来越长的警示语，力图预先标明种种可能发生的事故。Today, stepladders carry labels several inches long that warn, among other things, that you might -- surprise! -- fall off. The label on a child’s Batman cape cautions that the toy “does not enable user to fly.”如今，活梯上贴着几英寸长的警告标签，除了其他警告事项外，还警告你可能会摔下来，简直是莫名其妙！贴在儿童的蝙蝠侠披风上的标签也告诫说，本玩具“无法让用户飞行”。While warnings are often appropriate and necessary -- the dangers of drug interactions, for example -- and many are required by state or federal regulations, it isn’t clear that they actually protect the manufacturers and sellers from liability if a customer is injured. About 50 percent of the companies lose when injured customers take them to court.虽然警示语常常是合理而必要的（如警告药物有相互作用的危险），并且很多是州或联邦法规所要求的，但是当消费者受伤时，这些警示语能否真正保护制造商和销售商使之免于承担责任，却还很难说,被受伤的消费者告上法庭的公司中，大约一半会败诉。Now the tide appears to be turning.现在这种趋势似乎正在转变。As personal injury claims continue as before, some courts are beginning to side with defendants, especially in cases where a warning label probably wouldn’t have changed anything.尽管个人伤害索赔案件如以往一样不断发生，但有些法庭已开始站到被告一方，特别是在处理那些有警告标签也可能无法避免伤害的案件时。In May, Julie Nimmons, president of Schutt Sports in Illinois, successfully fought a lawsuit involving a football player who was paralyzed in a game while wearing a Schutt helmet.五月份,伊利诺斯州的Schutt体育公司总裁朱利·尼蒙斯就成功地打赢了这样一场官司。一名橄榄球队员戴着该公司的头盔在一场比赛中受伤瘫痪，遂将该公司告上法庭。“We’re really sorry he has become paralyzed, but helmets aren’t designed to prevent those kinds of injuries,” says Nimmons. The jury agreed that the nature of the game, not the helmet, was the reason for the athlete’s injury.尼蒙斯说：“他成了瘫痪，我们非常难过，但我们设计头盔不是为了预防这类伤害的。”陪审团也认为造成该运动员受伤的是这项运动本身的危险性，而不是头盔。At the same time, the American Law Institute -- a group of judges, lawyers, and academics whose recommendations carry substantial weight -- issued new guidelines for tort law stating that companies need not warn customers of obvious dangers or bombard them with a lengthy list of possible ones.与此同时，美国法学会——一群说话举足轻重的法官、律师、学者——发布了新的侵权法指导原则，宣布公司不必警示顾客那些显而易见的危险，或者给顾客列出一份冗长的可能遇到的危险的清单。“Important information can get buried in a sea of trivialities,” says a law professor at Cornell law School who helped draft the new guidelines. If the moderate end of the legal community has its way, the information on procts might actually be provided for the benefit of customers and not as protection against legal liability.康奈尔大学法学院一位参与起草新指导原则的教授说，“重要的信息会淹没在细枝末节的汪洋之中”。如果该法律团体的这一适中的目标能够实现，产品上提供的警示信息就不再是为回避法律责任而设，而是为保护消费者利益而提供了。试题：51. What were things like in 1980s when accidents happened?[A] Customers might be relieved of their disasters through lawsuits.[B] Injured customers could expect protection from the legal system.[C] Companies would avoid being sued by providing new warnings.[D] Juries tended to find fault with the compensations companies promised.52. Manufacturers as mentioned in the passage tend to.[A] satisfy customers by writing long warnings on procts[B] become honest in describing the inadequacies of their procts[C] make the best use of labels to avoid legal liability[D] feel obliged to view customers’ safety as their first concern53. The case of Schutt helmet demonstrated that.[A] some injury claims were no longer supported by law[B] helmets were not designed to prevent injuries[C] proct labels would eventually be discarded[D] some sports games might lose popularity with athletes54. The author’s attitude towards the issue seems to be.[A] biased[B] indifferent[C] puzzling[D] objective答案：B C A D

In the atmosphere, carbon dioxide acts rather like a one-way mirror -- the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping.大气中二氧化碳的作用类似于单向反射镜——如温室的玻璃屋顶，允许太阳光线的进入，同时又防止内部热量的散失。According to a weather expert’s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several metres and severely flooding coastal cities.根据气象专家的预测，若人类继续以当前的速度燃烧燃料，则2050年的大气层会比现在温度升高3℃。一旦这种温室效应真的发生，则极地冰盖会开始融化，从而使海面上升达几米，沿线城市出现严重洪水灾害。Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of earth’s chief food-growing zones.除此之外，大气温度的上升会使北半球的气候产生巨大变化，可能从而导致世界主要产粮区的改变。In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. 过去人们主要关注人为造成的全球变暖对北极的影响，因为南极圈比北极圈冷得多，且冰层也厚得多，But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming: in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.但现在，气候专家开始把更多的注意力放到了西南极圈─—因为几度的升温（换言之，未来五十年燃料燃烧所造成的升温）足可以影响该地区。Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.卫星图像表明：南极圈中大片区域已经开始消失。现有证据表明：温室效应已经发生。这与二氧化碳能使地球变暖的理论相符。However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling.但是，燃料燃烧最多的北半球温度不升反降。Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has most effect on the weather?对此，科学家得出的结论是：迄今为止，自然因素对天气的影响胜过人为因素。问题是，哪种自然因素对天气的影响最大。One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and “cold” spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days, it presents hotter or “colder” faces to the earth, and different aspects to different parts of the earth.一种可能是太阳行为的变化。某一研究站的气象学家已对太阳的热点和“冷点（相对较冷的地方）”进行了研究。太阳旋转时，以27.5天为周期向地球的不同地方展示其热点或“冷点”的不同方面。This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward.这似乎对地球大气压力的分布有相当大的影响，从而影响风流。同时，太阳也在做长期的变化：它的热量释放呈升——降交替变化，最近呈下降趋势。Scientists are now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not. 科学家们现在发现了太阳——天气互动模式和实际气候几千年间的变化（包括最后的冰川时代）之间的联系。问题是: 基于这种模式的预测，世界现在应该正在进入新的冰川时代，而实际上并没有。One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia (惯性) of the earth’s climate. If this is right, the warming effect of carbon dioxide might thus be serving as a useful counter-balance to the sun’s diminishing heat.对这个理论难题的解决方法是：假定太阳效应克服地球气候的惯性效应需要几千年时间。若此假定正确，则二氧化碳的温室效应会有助于抵消太阳热量的减少趋势。14. It can be concluded that a concentration of carbon dioxide in the atmosphere would.[A] prevent the sun’s rays from reaching the earth’s surface[B] mean a warming up in the Arctic[C] account for great changes in the climate in the northern hemisphere[D] raise the temperature of the earth’s surface[分析] 本题考核知识点：细节推理题。第一段将二氧化碳在大气中的作用类比温室的玻璃屋顶：允许阳光进入，并阻止内部热量的逃逸，（其结果是地球表面温度上升）。第二段首句则直接指出燃烧产生的二氧化碳会使大气温度上升。第四段指出：南极气候变化证明了二氧化碳使地球变暖的理论。所以，[D]为正确选项。[A]和第一段内容相反。第五段说明，北半球（包括北极圈）的气温在下降，所以，从文中无法推知[B]。[C]的错误在于其片面性。第五段指出：产生二氧化碳最多的北半球温度不升反降是因为：自然因素对北半球气候的影响大于人为因素，所以，北半球气候的变化是自然因素和人为因素作用的共同结果。15. The article was written to explain.[A] the greenhouse effect[B] the solar effects on the earth[C] the models of solar-weather interactions[D] the causes affecting weather[分析] 本题考核知识点：文章主旨题。解答文章主旨题需要对全文的综合理解。本文第一到四段为人为因素（温室效应）对天气的影响。第五至六段为自然因素（太阳行为的变化）对天气的影响。最后一段为人为因素和自然因素对地球气候的共同作用。所以，[D]为最恰当选项。[A]、[B]、[C] 的错误在于其片面性。[A]只是影响气候的人为因素，而[B]、[C]只涉及了影响气候的自然因素。16. Although the fuel consumption is greater in the northern hemisphere, temperatures there seem to be falling. This is.[A] mainly because the levels of carbon dioxide are rising[B] possible because the ice caps in the poles are melting[C] exclusively e to the effect of the inertia of the earth’s climate[D] partly e to variations in the output of solar energy[分析] 本题考核知识点：因果细节题。第五段第二句指出，北半球燃料燃烧产生二氧化碳最多，气温却不升反降是因为：迄今为止，自然因素的影响胜过人为因素。第六段进一步指出，对地球气候变化影响最大的“自然因素”是太阳行为的变化：太阳的运转影响风流（wind circulaltion）；太阳能量释放呈周期性变化。所以，太阳能释放的变化是北半球气温下降的原因之一，[D]为正确选项。二氧化碳含量上升导致的结果是气温上升，所以[A]不正确。[B]无中生有：文中没有提及极地冰盖融化和北半球气温下降之间的联系，而且根据常识也可排除。[C]的错误在于：误把抑制因素当成了形成因素。从第五、六段可知，北半球温度下降的原因是自然因素（尤其是太阳行为）的影响。而最后一段倒数第二句指出：地球气候的惯性与太阳效应是相反的过程，因此它应对地球变冷起抑制作用。另外，exclusively 的过于绝对也暗示这不是正确选项。但近年的考题已经在避免留给考生这样的线索。17. On the basis of their models, scientists are of the opinion that.[A] the climate of the world should be becoming cooler[B] it will take thousands of years for the inertia of the earth’s climate to take effect[C] the man-made warming effect helps to increase the solar effects[D] the new Ice Age will be delayed by the greenhouse effect[分析]本题考核知识点：文中人物观点推理题。第七段第二句说明：科学家们基于太阳——天气互动模式，预测出世界现在应该正在进入冰川时代，所以[A]为正确选项。[B]的错误在于对第七段第三句的理解错误。该句说明的是“太阳效应克服地球气候的惯性效应”，而非“地球气候的惯性发生效应”。[C]和原文内容相反。本文最后一句说明：目前二氧化碳的温室效应在对太阳效应产生抵消作用（counterbalance）。第七段第三句说明：延迟新的冰川时代的主要因素是地球气候的惯性作用，因此[D]不正确。18. If the assumption about the delay of a new Ice Age is correct,.[A] the best way to overcome the cooling effect would be to burn more fuels[B] ice would soon cover the northern hemisphere[C] the increased levels of carbon dioxide in the atmosphere could warm up the earth even more quickly[D] the greenhouse effect could work to the advantage of the earth[分析]本题考核知识点：文中细节推理题。文中最后一句说明：若此假说（关于冰川时代的延迟）正确，则温室效应可以对地球进入新的冰川时代起到遏制作用，这无疑是有利于地球的一面。所以，[D]为正确选项。[A]过度引申，文中仅仅提到大气温度上升有助于抵消太阳热量的减少，但燃烧燃料是否最好文中未提。[B]错误在于：北半球被冰覆盖不是冰川时代延迟的结果，而是冰川时代到来的后果。[C]属逻辑错误：冰川时代的延迟虽然与二氧化碳的温室效有关，但地球是否会“更快（even more）”变暖则文中未提。

原文+译文：In the first year or so of Web business, most of the action has revolved around efforts to tap the consumer market.网上商务开始的第一年左右，大部分活动都围绕着开拓消费者市场而进行。More recently, as the Web proved to be more than a fashion, companies have started to buy and sell procts and services with one another.最近，随着网络被证实不仅仅是一种时尚，公司便开始（在网上）相互交易产品和服务。Such business-to-business sales make sense because businesspeople typically know what proct they’re looking for.公司之间的这种交易非常合理，因为商人都清楚地知道他们需要的是产品。Nonetheless, many companies still hesitate to use the Web because of doubts about its reliability. “Businesses need to feel they can trust the pathway between them and the supplier,” says senior analyst Blane Erwin of Forrester Research. Some companies are limiting the risk by concting online transactions only with established business partners who are given access to the company’s private intranet.不过，由于怀疑网络的可靠性，许多公司仍对网络的使用犹豫不决。弗瑞斯特研究所的资深分析员布兰·欧文说，“商家需要感受到，他们可以信赖自己和供应商之间的这种沟通途径”。有些公司为了降低风险，只与固定的贸易伙伴进行在线贸易，给予这些伙伴进入本公司局域网的权利。Another major shift in the model for Internet commerce concerns the technology available for marketing.网络商业模式的另一个重大变化与可用于营销的技术有关。Until recently, Internet marketing activities have focused on strategies to “pull” customers into sites.直到最近，因特网上的营销活动还集中在使用将用户“拉进”网站的策略上。In the past year, however, software companies have developed tools that allow companies to “push” information directly out to consumers, transmitting marketing messages directly to targeted customers.然而去年，软件公司开发出新的技术，使公司可以将信息直接“推出”给消费者，直接把营销信息传送给特定的用户。Most notably, the Pointcast Network uses a screen saver to deliver a continually updated stream of news and advertisements to subscribers’ computer monitors.最突出的例子是Pointcast网络，该网络使用一种屏幕保护系统，将最新的信息和广告不断地传送到用户的计算机显示器上。Subscribers can customize the information they want to receive and proceed directly to a company’s Web site.用户可以量身设定自己想要接收的信息，然后直接进入某个公司的网址。Companies such as Virtual Vineyards are already starting to use similar technologies to push messages to customers about special sales, proct offerings, or other events.像Virtual Vineyards这样的公司业已开始采用类似的技术将有关特价销售、产品促销或其他活动的信息“推”向用户。But push technology has earned the contempt of many Web users.但这种“推”的技术遭到许多网上用户的鄙视。Online culture thinks highly of the notion that the information flowing onto the screen comes there by specific request.在线文化推崇这样一个理念：流动到屏幕上的信息应是在专门的请求之后才出现。Once commercial promotion begins to fill the screen uninvited, the distinction between the Web and television fades. That’s a prospect that horrifies Net purists.一旦商业促销不请自来地充斥着电脑屏幕，那么网络和电视就没多大差别了。这种前景让网络净化者感到不安。But it is hardly inevitable that companies on the Web will need to resort to push strategies to make money.公司在网上并不是非得依靠“推”的策略方能挣钱。The examples of Virtual Vineyards, Amazon.com, and other pioneers show that a Web site selling the right kind of procts with the right mix of interactivity, hospitality, and security will attract online customers.像Virtual Vineyards 和Amazon.Com及其他开拓者的例子表明：一个销售适类商品的网站，如果将互动、热情服务、安全相结合，肯定会吸引网上用户的。And the cost of computing power continues to free fall, which is a good sign for any enterprise setting up shop in silicon. People looking back 5 or 10 years from now may well wonder why so few companies took the online plunge.计算机计算能力的成本持续下降，对任何建立了网上销售点的企业来说都是个好的征兆。回顾过去的5年或10年，人们或许会感到奇怪。为什么只有这么少的公司尝试网上销售呢？试题：51. We learn from the beginning of the passage that Web business.[A] has been striving to expand its market[B] intended to follow a fanciful fashion[C] tried but in vain to control the market[D] has been booming for one year or so52. Speaking of the online technology available for marketing, the author implies that.[A] the technology is popular with many Web users[B] businesses have faith in the reliability of online transactions[C] there is a radical change in strategy[D] it is accessible limitedly to established partners53. In the view of Net purists,.[A] there should be no marketing messages in online culture[B] money making should be given priority to on the Web[C] the Web should be able to function as the television set[D] there should be no online commercial information without requests54. We learn from the last paragraph that.[A] pushing information on the Web is essential to Internet commerce[B] interactivity, hospitality and security are important to online customers[C] leading companies began to take the online plunge decades ago[D] setting up shops in silicon is independent of the cost of computing power答案：A C D B

原文+译文：When a Scottish research team startled the world by revealing 3 months ago that it had cloned an alt sheep, President Clinton moved swiftly. 三个月前，当一个苏格兰研究小组宣布他们克隆了一只成年绵羊时，世界为之震惊，克林顿总统迅速做出反应。Declaring that he was opposed to using this unusual animal husbandry technique to clone humans, he ordered that federal funds not be used for such an experiment -- although no one had proposed to do so -- and asked an independent panel of experts chaired by Princeton President Harold Shapiro to report back to the White House in 90 days with recommendations for a national policy on human cloning.他宣称反对利用这种非同寻常的畜牧业技术去克隆人，并下令禁止联邦资金用于此类实验——尽管还没有人提议要那样做——并要求一个由普林斯顿大学校长哈罗德·夏皮罗为首的独立专家小组，在九十天内拿出有关克隆人的国家政策的建议，向白宫汇报。That group -- the National Bioethics Advisory Commission (NBAC) -- has been working feverishly to put its wisdom on paper, and at a meeting on 17 May, members agreed on a near-final draft of their recommendations.这个名为“全国生物伦理道德顾问委员会”（NBAC）的小组一直在非常积极地工作，集思广益，并诉诸笔端；在5月17日的一次会议上，委员们就接近定稿的意见书取得了一致意见。NBAC will ask that Clinton’s 90-day ban on federal funds for human cloning be extended indefinitely, and possibly that it be made law.NBAC将要求克林顿总统禁止联邦资金用于克隆人的九十天禁令无限期地延长，并且还可能要求将之立法。But NBAC members are planning to word the recommendation narrowly to avoid new restrictions on research that involves the cloning of human DNA or cells -- routine in molecular biology.但是，NBAC成员们正计划在建议的措辞上更为严谨，以避免给克隆人体DNA或细胞等研究带来更多的限制——（这属于）分子生物研究中的常规课题。The panel has not yet reached agreement on a crucial question, however, whether to recommend legislation that would make it a crime for private funding to be used for human cloning.然而，该小组尚未在一个关键问题上达成一致，即是否建议立法机关将私人资金用于克隆人的行为法定为犯罪。In a draft preface to the recommendations, discussed at the 17 May meeting, Shapiro suggested that the panel had found a broad consensus that it would be “morally unacceptable to attempt to create a human child by alt nuclear cloning.”在5月17日会议上讨论的建议序言草案中，夏皮罗表示，专家组已取得广泛的共识，认为“试图利用成人细胞核去克隆婴儿将是违背道德伦理的”。Shapiro explained ring the meeting that the moral doubt stems mainly from fears about the risk to the health of the child. The panel then informally accepted several general conclusions, although some details have not been settled.夏皮罗解释说在与会期间，道德上的怀疑主要源于对婴儿健康的担忧。随后，该小组非正式地接受了几项概括性的结论，尽管有些细节尚无定论。NBAC plans to call for a continued ban on federal government funding for any attempt to clone body cell nuclei to create a child. Because current federal law already forbids the use of federal funds to create embryos (the earliest stage of human offspring before birth) for research or to knowingly endanger an embryo’s life, NBAC will remain silent on embryo research.NBAC计划呼吁继续禁止为任何企图利用人体细胞核去制造婴孩的做法提供联邦政府基金资助。因为现行的联邦法律已经禁止联邦基金用于制造研究用的胚胎(人类后代出生前的最早阶段)或有意识地危及胚胎的生命，所以NBAC在胚胎研究这一问题上将保持沉默。NBAC members also indicated that they will appeal to privately funded researchers and clinics not to try to clone humans by body cell nuclear transfer. NBAC的成员明确表示，他们将呼吁受私人基金资助的研究人员和诊所不要尝试通过人体细胞核转移来克隆人。But they were divided on whether to go further by calling for a federal law that would impose a complete ban on human cloning. Shapiro and most members favored an appeal for such legislation, but in a phone interview, he said this issue was still “up in the air.”但他们在是否进一步要求联邦立法强令完全禁止克隆人这一问题上存在分歧。夏皮罗和大多数委员赞成将此立法，但在电话采访中，他透露这一议题仍“悬而未决”。试题：51. We can learn from the first paragraph that.[A] federal funds have been used in a project to clone humans[B] the White House responded strongly to the news of cloning[C] NBAC was authorized to control the misuse of cloning technique[D] the White House has got the panel’s recommendations on cloning52. The panel agreed on all of the following except that.[A] the ban on federal funds for human cloning should be made a law[B] the cloning of human DNA is not to be put under more control[C] it is criminal to use private funding for human cloning[D] it would be against ethical values to clone a human being53. NBAC will leave the issue of embryo research undiscussed because_.[A] embryo research is just a current development of cloning[B] the health of the child is not the main concern of embryo research[C] an embryo’s life will not be endangered in embryo research[D] the issue is explicitly stated and settled in the law54. It can be inferred from the last paragraph that.[A] some NBAC members hesitate to ban human cloning completely[B] a law banning human cloning is to be passed in no time[C] privately funded researchers will respond positively to NBAC’s appeal[D] the issue of human cloning will soon be settled答案：B C D A

原文+译文：Science, in practice, depends far less on the experiments it prepares than on the preparedness of the minds of the men who watch the experiments.实际上，科学的进步依赖于做实验，但更依赖于实验的观察者（即做实验的人）有所准备的头脑。Sir Isaac Newton supposedly discovered gravity through the fall of an apple.据说艾萨克·牛顿爵士是从苹果落地现象中发现了万有引力。Apples had been falling in many places for centuries and thousands of people had seen them fall. But Newton for years had been curious about the cause of the orbital motion of the moon and planets.多少个世纪以来，许多地方一直都有苹果落到地面，成千上万的人也都看过苹果落地。但多年来只有牛顿一直对月球和行星沿轨道运行的起因感到好奇。What kept them in place? Why didn’t they fall out of the sky? The fact that the apple fell down toward the earth and not up into the tree answered the question he had been asking himself about those larger fruits of the heavens, the moon and the planets.是什么使它们保持在现在的位置？它们为什么不从天上掉下来？苹果向下落到地面而不向上飞到树上，这一事实回答了他长期以来一直对天空中更大的“果实”——月球和行星所存有的疑问。How many men would have considered the possibility of an apple falling up into the tree?多少人会考虑过苹果向上飞到树上的可能性呢？Newton did because he was not trying to predict anything. He was just wondering. His mind was ready for the unpredictable. Unpredictability is part of the essential nature of research.牛顿这样做了，因为他不想对任何事情进行预测。他只是怀有好奇心。他的头脑在准备思考不可预测的事。不可预测性是科学研究的一个基本特征。If you don’t have unpredictable things, you don’t have research. Scientists tend to forget this when writing their cut and dried reports for the technical journals, but history is filled with examples of it.如果没有不可预测现象的产生就无所谓科学研究了。科学家们在为学术刊物撰写呆板的例行报告时往往会忘记这一点，而历史上这样的例子却比比皆是。In talking to some scientists, particularly younger ones, you might gather the impression that they find the “scientific method” a substitute for imaginative thought.在和一些科学家，特别是年轻科学家交谈时，你可能会有这样一种印象：他们认为“科学方法”可以代替创造性思维。I’ve attended research conferences where a scientist has been asked what he thinks about the advisability of continuing a certain experiment.我出席过一些科研会议，会上有人问一位科学家继续某项实验是否是明智之举。The scientist has frowned, looked at the graphs, and said “the data are still inconclusive.”那位科学家皱了皱眉，又看了看图表，然后说：“数据还是不够确定。”“We know that,” the men from the budget office have said, “but what do you think? Is it worthwhile going on? What do you think we might expect?” The scientist has been shocked at having even been asked to speculate.预算部门的人说：“这点我们知道，但你的意见如何？你觉得值得做下去吗？你觉得我们可以期待什么呢？”这位科学家感到很震惊，他没有料到人们会让他做出预测。What this amounts to, of course, is that the scientist has become the victim of his own writings.当然，这几乎等于说：这位科学家成了自己所写报告的受害者。He has put forward unquestioned claims so consistently that he not only believes them himself, but has convinced instrial and business management that they are true.他所提出的种种论断是如此不容置疑、如此一致，以至于不仅他自己相信了，而且也说服了工商界的管理者相信其正确性。If experiments are planned and carried out according to plan as faithfully as the reports in the science journals indicate, then it is perfectly logical for management to expect research to proce results measurable in dollars and cents.假如科学实验像科学杂志报告显示的那样完全按事先的计划去规划和实施，那么，对管理层来说，期待研究能够产生可用美元、美分衡量的结果是完全合理的。It is entirely reasonable for auditors to believe that scientists who know exactly where they are going and how they will get there should not be distracted by the necessity of keeping one eye on the cash register while the other eye is on the microscope.审计人员也完全有理由相信，确切知道自己的目标并知道如何实现这一目标的科学家们根本没必要分心：用一只眼盯着现金计数器的同时，用另一只眼睛盯着显微镜。Nor, if regularity and conformity to a standard pattern are as desirable to the scientist as the writing of his papers would appear to reflect, is management to be blamed for discriminating against the “odd balls” among researchers in favor of more conventional thinkers who “work well with the team.”如果像他们的论文所反映的那样，科学家渴望规律性和与某种标准模式的一致性，那么管理人员歧视研究人员中的“标新立异者”，而赞赏“善于合作”的具有传统思维模式的人，也就是无可指摘的。试题：51. The author wants to prove with the example of Isaac Newton that.[A] inquiring minds are more important than scientific experiments[B] science advances when fruitful researches are concted[C] scientists seldom forget the essential nature of research[D] unpredictability weighs less than prediction in scientific research52. The author asserts that scientists.[A] shouldn’t replace “scientific method” with imaginative thought[B] shouldn’t neglect to speculate on unpredictable things[C] should write more concise reports for technical journals[D] should be confident about their research findings53. It seems that some young scientists.[A] have a keen interest in prediction[B] often speculate on the future[C] think highly of creative thinking[D] stick to “scientific method”54. The author implies that the results of scientific research.[A] may not be as profitable as they are expected[B] can be measured in dollars and cents[C] rely on conformity to a standard pattern[D] are mostly underestimated by management答案：A B D A

本文说明了水对于生长的植物的重要作用。第一段：Most growing plants contain much more water than all other materials combined.大部分生长的植物，其水的含量超过其他所有物质的含量总和。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.C·R·巴恩斯认为，把植物叫做水结构就如同把主要用砖盖成的房子叫做砖建筑一样恰当。Certain it is that all essential processes of plant growth and development occur in water.当然，植物生长的一切必要过程都发生于水中。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.来自于土壤的矿物质在被植物根茎吸收之前，必须先溶解于水。They are carried to all parts of the growing plant and are built into essential plant materials while in a dissolved state.它们在溶解状态被输送到植物的全身并构成基本的植物材料。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.空气中的二氧化碳能以气体的形式进入叶子，但在和一部分水结合生成单糖（构成植物体最基本的材料）之前也必须先溶于水。Actively growing plant parts are generally 75 to 90 percent water.植物生长活跃部分的含水量一般高达75-90%。Structural parts of plants, such as woody stems no longer actively growing, may have much less water than growing tissues.植物的结构部分（如生长不活跃的木质茎）的含水量可能大大少于生长活跃的组织。第二段：The actual amount of water in the plant at any one time, however, is only a very small part of what passes through it ring its development.但是，植物任何时候的实际含水量都只是其生长期间通过它全身水量的很小一部分。The processes 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.借助叶绿素和光能量发生光合作用（二氧化碳和水结合）以形成单糖的过程要求二氧化碳从空气中进入植物。This occurs mainly in the leaves. The leaf surface is not solid but contains great numbers of minute openings, through which the carbon dioxide enters.这一过程主要发生在叶子上。叶子表面并非固体，而是有大量的小口。二氧化碳通过这些小口进入植物。The same structure that permits the one gas to enter the leaf, however, permits another gas -- water vapor -- to be lost from it.这些允许二氧化碳进入叶子的小口却让另一种气体——水蒸气散失。Since carbon dioxide is present in the air only in trace quantities (3 to 4 parts in 10,000 parts of air) and water vapor is near saturation in the air spaces within the leaf (at 80℉, 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.由于二氧化碳在空气中的含量非常少（3-4‰），且叶子内部空气空间的水蒸气含量接近饱和状态（80F时，饱和状态下的每10000份空气中含186份水汽），所以，植物失去的水蒸气的量是吸收的二氧化碳量的许多倍。Actually, because of wind and other factors, the loss of water in proportion to carbon dioxide intake may be even greater than the relative concentrations of the two gases.实际上，因为风和其他因素的影响，损失掉的水和吸入二氧化碳的比甚至可能大于这两种气体的相对浓度。Also, not all of the carbon dioxide that enters the leaf is synthesized into carbohydrates (碳水化合物).另外，并非所有进入叶子的二氧化碳都可以被合成碳水化合物。19. A growing plant needs water for all of the following except .[A] forming sugars[B] sustaining woody stems[C] keeping green[D] procing carbon dioxide[分析] 本题考核知识点：事实细节题。第一段第六句（the carbon dioxide…mainly built）和第二段第二句说明：二氧化碳可以直接从空气中进入植物的叶子里，所以不需要水。[D]选项正确。同时这两句还说明：生成糖的过程需要二氧化碳先溶于水，然后和水结合，所以[A]不是正确选项。第一段最后一句说明：（尽管木质茎比活跃组织需要的水少得多），但还是需要一定量的水。所以，[B]非正确选项。[C]文中未提及。20. 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[分析]本题考核知识点：文中细节推理题。第一段第五句说明：二氧化的作用主要是生成植物体最需要的材料——单糖。第二段第二句说明：植物的光合作用（二氧化碳和水结合）形成单糖。所以，光合作用能够提供植物需要的（单）糖。[A]为正确选项。[B]的干扰来自于第二段第二句，但该句提到的是从光中获取能量是光合作用的条件之一，而不是反过来通过光合作用去获取能量。[C]文中未提及。[D]是光合作用的过程，而不是作用。21. The second paragraph uses facts to 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[分析] 本题考核知识点：段落主旨题。解此题需要分析第二段的结构。本段第一句为段落主题句：植物的含水量只是其需水量很小的一部分。然后用事实说明为什么会出现这种情况（植物叶子允许二氧化碳进入，却让水蒸气散失。再加上风和其他因素的作用，大部分的水都损失掉了）。所以，[C]为正确选项。[A]“有效利用水”不是本文涉及的内容；[B]只在第一段有所提及。第二段提到风等因素造成水的损失，但并未提到风的大小与损失的水蒸汽的量相关。所以，[D]排除。22. According to the passage, which of the following statements is TRUE?[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 synthesized.[分析] 本题考核知识点：文中多处细节理解题。文章第二段最后一句指出：并非所有进入叶子的二氧化碳都被合成了碳水化合物。这说明[D]选项正确。[A]的干扰来自于第一段第四句。该句说明，来自于土壤中的矿物质元素只有先溶于“土壤溶液”才能被“根部”吸收，而非溶解于“根部”。[B]与原文内容相反：从第一段最后一句可知，生长不活跃的木质茎含水量可能远远小于生长活跃的叶子。[C]与文中内容不符：第二段第五句给出的信息是：“叶子内部”空气中的水蒸气含量“接近”饱和状态，而非“叶子周围”的空气“处于”饱和状态。23. 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[分析] 本题考核知识点：文章主旨题。本文第一段首先通过类比开门见山地说明水对于生长中植物的重要作用。然后通过水对植物生长的各种功能（溶解矿物质元素、溶解二氧化碳并和二氧化碳结合生成单糖）说明植物生长中的一切重要过程都离不开水。第二段用事实说明：（尽管植物含水量相当高），但植物生长所需要的水远远大于其本身所所含有的水。所以，整篇文章说围绕的中心是：水对于植物生长的重要作用。[B]为正确选项。考生误选[A]、[C]、[D]都是因为对光合作用在全文中作用的理解错误：文中提到关于二氧化碳（光合作用）是为了用事实说明水对植物生长的重要作用，而并非为了说明二氧化碳本身或光合作用（生成单糖）的作用，所以[A]、[C]都不正确；同样也不是为了说明光合作用的过程，所以[D]错误。