2015年考研英語二作文模擬試卷及答案

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　　 2015考研英語閱讀理解模擬題及答案(理學類10套)1

　　Scientists have known since 1952 that DNA is the basic stuff of heredity. They've known its chemical structure since 1953. They know that human DNA acts like a biological computer program some 3 billion bits long that spells out the instructions for making proteins， the basic building blocks of life.

　　But everything the genetic engineers have accomplished during the past half-century is just a preamble to the work that Collins and Anderson and legions of colleagues are doing now. Collins leads the Human Genome Project， a 15-year effort to draw the first detailed map of every nook and cranny and gene in human DNA. Anderson， who pioneered the first successful human gene-therapy operations， is leading the campaign to put information about DNA to use as quickly as possible in the treatment and prevention of human diseases.

　　What they and other researchers are plotting is nothing less than a biomedical revolution. Like Silicon Valley pirates reverse-engineering a computer chip to steal a competitor's secrets， genetic engineers are decoding life's molecular secrets and trying to use that knowledge to reverse the natural course of disease. DNA in their hands has become both a blueprint and a drug， a pharmacological substance of extraordinary potency that can treat not just symptoms or the diseases that cause them but also the imperfections in DNA that make people susceptible to a disease.

　　And that's just the beginning. For all the fevered work being done， however， science is still far away from the Brave New World vision of engineering a perfect human—or even a perfect tomato. Much more research is needed before gene therapy becomes commonplace， and many diseases will take decades to conquer， if they can be conquered at all.

　　In the short run， the most practical way to use the new technology will be in genetic screening. Doctors will be able to detect all sorts of flaws in DNA long before they can be fixed. In some cases the knowledge may lead to treatments that delay the onset of the disease or soften its effects. Someone with a genetic predisposition to heart disease， for example， could follow a low-fat diet. And if scientists determine that a vital protein is missing because the gene that was supposed to make it is defective， they might be able to give the patient an artificial version of the protein. But in other instances， almost nothing can be done to stop the ravages brought on by genetic mutations. (409 words)

　　1. It can be inferred from the text that Collins and Anderson and legions of colleagues _____.

　　[A] know that human DNA acts like a biological computer program

　　[B] have found the basic building blocks of life

　　[C] have accomplished some genetic discovery during the past half-century

　　[D] are making a breakthrough in DNA

　　2. Collins and Anderson are cited in the text to indicate all the following EXCEPT that ______.

　　[A] time-consuming effort is needed to accomplish the detailed map of in human DNA

　　[B] human gene-therapy operations may be applied to the patients

　　[C] gene-therapy now is already generally used to the treatment and prevention of human diseases

　　[D] information about DNA may be used in the treatment and prevention of human diseases

　　3. The word “pirate” (line 2， paragraph 3) means______.

　　[A] one who robs at sea or plunders the land from the sea

　　[B] one who makes use of or reproduces the work of another without authorization

　　[C] to take (something) by piracy

　　[D] to make use of or reproduce (another's work) without authorization

　　4. We can draw a conclusion from the text that_____.

　　[A] engineering a perfect human is not feasible for the time being

　　[B] it‘s impossible for scientists to engineer a perfect tomato

　　[C] many diseases will never be conquered by human beings

　　[D] doctors will be able to cure all sorts of flaws in DNA in the long run

　　5. The best title for the text may be ______.

　　[A] DNA and Heredity

　　[B] The Genetic Revolution

　　[C] A Biomedical Revolution

　　[D] How to Apply Genetic Technology

　　詞匯注釋

　　stuff 物質(zhì)

　　preamble 開端

　　nook and cranny 排列

　　potency 力量

　　susceptible 易受感染的

　　predisposition 易患病的體質(zhì)

　　難句講解

　　1. They know that human DNA acts like a biological computer program some 3 billion bits long that spells out the instructions for making proteins， the basic building blocks of life.

　　[簡析] 本句話的主干是“They know that…”。they 指的是前面句子中提到的scientists;第一個引導的是賓語從句，some 3 billion bits long修飾computer program，第二個that也修飾computer program;the basic building blocks of life是在解釋proteins.

　　2. Anderson， who pioneered the first successful human gene-therapy operations， is leading the campaign to put information about DNA to use as quickly as possible in the treatment and prevention of human diseases.

　　[簡析] 本句話的主干是“Anderson is leading the campaign…”。Who引導的非限定性定語從句，修飾Anderson;to put information…短語修飾campaign，其中的to use…作目的狀語。

　　3. DNA in their hands has become both a blueprint and a drug， a pharmacological substance of extraordinary potency that can treat not just symptoms or the diseases that cause them but also the imperfections in DNA that make people susceptible to a disease.

　　[簡析] 本句話的主干是“DNA has become both a blueprint and a drug”。in their hands修飾DNA;a pharmacological substance…是在解釋前面的drug，其中的第一個that 引導的定語從句修飾pharmacological substance;第二個that引導的定語從句修飾imperfections.

　　4. And if scientists determine that a vital protein is missing because the gene that was supposed to make it is defective， they might be able to give the patient an artificial version of the protein.

　　[簡析] 本句話的主干是“…they might be able to give the patient an artificial version of the protein”。If引導的是條件狀語從句，其中的第一個that引導的是賓語從句，because引導的時原因狀語從句;第二個that引導的定語從句修飾gene.

　　答案與解析

　　36. D 推論題。本題的問題是“根據(jù)本文，可以推知：柯林斯、安德森以及他們的眾多同事”。題干中的“Collins and Anderson and legions of colleagues”出自文章第二段第一句話中，表明本題與第二段有關(guān)。第二段提到，柯林斯領(lǐng)導了“人類基因工程”研究項目，而安德森首創(chuàng)了人類第一次成功的基因治療手術(shù)，并且正在領(lǐng)導一項有關(guān)DNA的研究活動;第三段接著介紹了他們掌握的DNA的作用。由此可知，這些研究人員對DNA的研究正在取得進步。[D]“正在取得DNA領(lǐng)域的突破”是對文中相關(guān)信息的概括，為正確答案。[A]“知道人類的DNA的作用就像一個生物學計算機程序”和[C]“在過去半個世紀里完成了一些基因發(fā)現(xiàn)”是第一段中提到的以前科學家的成果，不是柯林斯、安德森以及他們的同事的成果;[B]“發(fā)現(xiàn)了生命的基本構(gòu)造元素”是針對文中“spells out the instructions for making proteins，the basic building blocks of life”這句話設(shè)置的干擾項。生命的基本構(gòu)造元素是蛋白質(zhì)，但這并不是這些研究人員發(fā)現(xiàn)的，所以[B]不對。

　　37. C 結(jié)構(gòu)題。本題的問題是“文中引用柯林斯和安德森是為了表示下面各項，除了”。題干中的“Collins and Anderson”出自文章第二段第一句話中，表明本題與第二段有關(guān)。第二段提到這兩人時指出，柯林斯領(lǐng)導的研究項目歷時15年，旨在繪制第一張人類DNA基因排列詳細圖表，而安德森首創(chuàng)了人類第一次成功的基因治療手術(shù)，他正在領(lǐng)導的研究準備把有關(guān)DNA的信息盡可能迅速地用于治療并預防人類的疾病;第三段提到，他們掌握的DNA可以治療癥狀或者導致癥狀的疾病。這說明，[A]“為了完成人類DNA的詳細基因圖，需要付出很大的努力”、[B]“人類基因療法手術(shù)可能被用來治療患者一和[D]”有關(guān)DNA的信息可能被用來治療并預防人類的疾病“體現(xiàn)了提到這兩人的目的。[C]”如今，基因療法普遍用于治療并預防人類的疾病“明顯與第四段第三句話的意思不符。

　　38. B 詞義題。本題的問題是“單詞‘pirate’(第三段第二行)最可能的意思是”。第三段提到該詞時是說，這些人反向設(shè)計一種電腦芯片去竊取競爭對手的秘密。根據(jù)“Sili.”Vailev“可知，[A]”一個在海上搶劫或者從海上搶劫陸地的人“不對;本句話是把該詞與genetic，engineers進行比較，說明該詞應該是指_人，所以，[C]”通過盜版獲得(某物)“和 [D]”沒有得到授權(quán)利用或者復制(他人工作)“不對。只有[B]”一個沒有得到授權(quán)利用或者復制他人工作的人“符合文意。

　　39. A 歸納題。本題的問題是“根據(jù)本文，我們可以得出結(jié)論”。文章前面三段介紹了遺傳工程師取得的成就，第四段指出，科學離實現(xiàn)設(shè)定一個完美人類的夢想還很遙遠，孝基因療法普遍之前，人們還需要進行更多的研究。這說明，目前的科學還不能設(shè)定一個完美人類。[A]“設(shè)定完美的人目前還不可行”是對文中相關(guān)信息的改寫，為正確答案。文中是說科學離設(shè)定完美土豆的夢想很遙遠，但并沒有說不可能，所以[B]“科學家要想設(shè)定一個完美的土豆是不可能的”與文意不符;[C]“許多疾病永遠也不會被人類征服”是針對第四段最后一句話設(shè)置的干擾項，文中是說“許多疾病也需要花費幾十年的時間去征服，如果它們可以被人類完全征服的話”，并不能說人類不能征服許多疾病，所以[C]不對;文中只是說“醫(yī)生可以檢測DNA中的所有缺陷”，并沒有說可以治愈，所以[D] “從長遠來看，醫(yī)生可能治愈DNA中的所有缺陷”不對。

　　40. B 主旨題。本題的問題是“本文的標題可能是”。文章前面幾段介紹了遺尊工程師取得的成就，后面兩段介紹了科學家在將基因療法用于治療疾病方面面臨的問題。這說明，本文主要是介紹基因領(lǐng)域的研究。[B]“基因革命”是對本文的恰當概括，可以表達本文的主題，為正確答案。DNA是科學家研究的具體內(nèi)容，不是本文探討的主題，所以[A]“DNA與遺傳”不能表達本文的主題;[C]“一場生物醫(yī)學革命”概念太廣，不準確;有關(guān)新技術(shù)的利用是最后一段的內(nèi)容，比較片面，所以[D]“如何應用基因技術(shù)”不能表達本文的主題。It has long been known that the rate of oxidative metabolism (the process that uses oxygen to convert food into energy) in any animal has a profound effect on its living patterns. The high metabolic rate of small animals， for example， gives them sustained power and activity per unit of weight， but at the cost of requiring constant consumption of food and water. Very large animals， with their relatively low metabolic rates， can survive well on a sporadic food supply， but can gen- erate little metabolic energy per gram of body weight. If only oxidative metabolic rate is considered， there- fore， one might assume that smaller， more active， animals could prey on larger ones， at least if they attacked in groups. Perhaps they could if it were not for anaerobic glycolysis， the great equalizer.

　　Anaerobic glcolysis is a process in which energy is produced， without oxygen， through the breakdown of muscle glycogen into lactic acid and adenosine tri- phosphate (ATP)， the energy provider. The amount of energy that can be produced anaerobically is a function of the amount of glycogen present-in all vertebrates about 0.5 percent of their muscles' wet weight. Thus the anaerobic energy reserves of a verte- brate are proportional to the size of the animal. If， for example， some predators had attacked a 100-ton dinosaur， normally torpid， the dinosaur would have been able to generate almost instantaneously， via anaerobic glycolysis， the energy of 3，000 humans at maximum oxidative metabolic energy production. This explains how many large species have managed to compete with their more active neighbors： the compensation for a low oxidative metabolic rate is glycolysis.

　　There are limitations， however， to this compensa- tion. The glycogen reserves of any animal are good， at most， for only about two minutes at maximum effort， after which only the normal oxidative metabolic source of energy remains. With the conclusion of a burst of activity， the lactic acid level is high in the body fluids， leaving the large animal vulnerable to attack until the acid is reconverted， via oxidative metabolism， by the liver into glucose， which is then sent (in part) back to the muscles for glycogen resyn- thesis. During this process the enormous energy debt that the animal has run up through anaerobic glycolysis must be repaid， a debt that is proportionally much greater for the larger vertebrates than for the smaller ones. Whereas the tiny shrew can replace in minutes the glycogen used for maximum effort， for example， the gigantic dinosaur would have required more than three weeks. It might seem that this inter- minably long recovery time in a large vertebrate would prove a grave disadvantage for survival. Fortunately， muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.

　　1. What is the text mainly about?。

　　[A] refute a misconception about anaerobic glycolysis.

　　[B] introduce a new hypothesis about anaerobic glycolysis.

　　[C] describe the limitations of anaerobic glycolysis.

　　[D] explain anaerobic glycolysis and its effects on animal survival.

　　2. According to the author， glycogen is crucial to the process of anaerobic glyrolysis because glycogen

　　[A] increases the organism‘s need for ATP.

　　[B] reduces the amount of ATP in the tissues.

　　[C] is an inhibitor of the oxidative metabolic production of ATP.

　　[D] is the material form which ATP is derived.

　　3. It is implied that the total anaerobic energy reserves of a vertebrate are proportional to its size because

　　[A] larger vertebrate conserve more energy than smaller vertebrates.

　　[B] larger vertebrates use less oxygen per unit weight than smaller vertebrates.

　　[C] the ability of a vertebrate to consume food is a function of its size.

　　[D]the amount of muscle tissue in a vertebrate is directly related to its size，

　　4. According to the text， a major limitation of anaerobic glycolysis is that it can

　　[A] produce in large animals more lactic acid than the liver can safely reconvert.

　　[B] necessitate a dangerously long recovery period in large animals.

　　[C] reduce energy more slowly than it can be used by large animals.

　　[D]consume all of the available glycogen regardless of need.

　　5. Which of the following audiences is the author most probably addressing?

　　[A] College students in an introductory course on animal physiology.

　　[B] Historians of science investigating the discovery of anaerobic glycolysis.

　　[C] Graduate students with specialized training in comparative anatomy.

　　[D] Zoologists interested in prehistoric animals.

　　參考答案：

　　1. D 主旨題。本題的問題是“本文主要是關(guān)于什么?”文章第一段首先提到動物的氧化新陳代謝率對其生存方式造成的影響，隨后引出了無氧糖酵解這個概念;第二段解釋了無氧糖酵解，第三段介紹了無氧糖酵解的局限性以及對動物的生存產(chǎn)生的影響。這說明[D]“解釋無氧糖酵解及其對動物生存產(chǎn)生的影響”可以表達本文的主題，為正確答案。文中沒有提到有關(guān)無氧糖酵解的錯誤觀念和新假說，所以[A]“反駁有關(guān)無氧糖酵解的一個錯誤概念”和[B]“介紹有關(guān)無氧糖酵解的一種新假說”屬于無中生有;[C]“描述無氧糖酵解的局限性”只是第三段的內(nèi)容，比較片面，不能表達本文的主題。

　　2. D 細節(jié)題。本題的問題是“根據(jù)作者的觀點，糖原質(zhì)對于無氧糖酵解的過程至關(guān)重要。因為糖原質(zhì)——”。題干中的“glycogen”出自文章第二段第一句話中，表明本題與第二段有關(guān)。第二段在解釋無氧糖酵解時提到，無氧糖酵解可以產(chǎn)生能量是糖原質(zhì)存在的作用，其能量是由、肌糖原質(zhì)分解成乳酸和三磷酸腺苷而產(chǎn)生的，而能量的供應者是三磷酸腺苷。這說明，糖原質(zhì)是無氧糖酵解的能量來源，也就是三磷酸腺苷的來源。[D]“是從中獲得三磷酸腺苷的物質(zhì)”是對文章第二段中“through the breakdown of muscle glycogen into lactic acid and adenosine triphosphate(ATP)”這句話的改寫，為正確答案。文中沒有提到加大三磷酸腺苷的需求和降低其含量的問題，所以[A]“加大了生物體對三磷酸腺苷的需求”和[B]“降低了組織中三磷酸腺苷的含量”屬于無中生有;[C]“是三磷酸腺苷的氧化新陳代謝生產(chǎn)的抑制者”與文意相反。

　　3. D 推論題。本題的問題是“文中暗示，脊椎動物的總無氧能源儲備與其體型大小相稱，因為 ”。題干中的“are proportional to its size”出自文章第二段第三句話中，表明本題與第二段有關(guān)。第二段提到，糖原質(zhì)大約占脊椎動物肌肉凈重的0.5%，所以脊椎動物的無氧性能量儲存同其體型的大小相稱;隨后列舉的恐龍例if-解釋了其中的原翻：由于恐龍的體型龐大，所以它可以通過無氧糖酵解在瞬間產(chǎn)生很大的能量。由此可知。肌肉越多，糖原質(zhì)的含量就越多，而只有體型越大，肌肉才越多。[D]“脊椎動物體內(nèi)的肌肉組織量同其體型大小直接相關(guān)”是對文章第二段中“the anaerobic energy reserves of a vertebrate are proportional to the size of the animal”這句話的改寫，為正確答案。[A]“較大的脊椎動物儲備的能量比較小的脊椎動物多”是針對文中“the anaerobic energy reserves of a vertebrate are proportional to the size of the animal”這句話設(shè)置的干擾項。而文中說的是脊椎動物的無氧性能量儲存，并不是脊椎動物儲備的能量，屬于偷換概念，所以不對;文中只提到了消耗食物和水的問題，沒有提到消耗氧氣的問題，所以[B]“較大的脊椎動物每單位體重消耗的氧氣比較小的脊椎動物少”屬于偷換概念;[C]“脊椎動物消耗食物的能力是其體型的作用”是對文中“The amount of energy that can be produced anaerobically is a functi0n of the amount of glycogen present”這句話的篡改，與文意不符。

　　4. B 細節(jié)題。本題的問題是“根據(jù)本文的觀點，無氧糖酵解的一個主要局限性就是，‘它能夠 ”。題干中的“l(fā)imitation”出自文章第三段第一句話中，表明本題與第三段有關(guān)。第三段解釋了補償?shù)木窒扌裕赋?，動物由于無氧糖酵解所導致的大量能量消耗必須得到補償;隨后舉例說，小地鼠在幾分鐘內(nèi)就能補償其最劇烈運動所消耗的糖原質(zhì)。但體型龐大的恐龍卻需要三個多星期才能完成補償。這說明，其主要局限性就是大型動物的補償期時間長。[B]“使大型動物必須有長時間的補償期”是對文中“the gigantic dinosaur would have required more than three weeks”這句話的改寫，為正確答案。文中提到“reconvert”時是說“一陣劇烈運動結(jié)束后，體液中乳酸的含量就高，這使得大型動物容易受到攻擊，直到乳酸通過氧化新陳代謝由肝臟再次轉(zhuǎn)化成葡萄糖”，說明[A]“在大型動物體內(nèi)生產(chǎn)的乳酸比肝臟可以再次轉(zhuǎn)化的乳酸多”屬于偷換概念;[C]“使能量減少的速度慢于大型動物使用能量的速度”與文意相反;[D]“消耗所有可以利用的糖原質(zhì)，不管需不需要”與第三段最后一句話的意思不符。

　　5. A 推論題。本文的問題是“作者最可能針對下面哪類聽眾發(fā)表演說?”作者主要是介紹無氧糖酵解對動物的生存產(chǎn)生的影響，他的解釋清楚易懂，沒有提到深奧難懂的知識。由此可知，作者最可能是針對初學動物學的學生這類讀者。[A]“動物生理學入門課的大學生”為正確答案。本文只是提到了無氧糖酵解，沒有介紹如何發(fā)現(xiàn)它，并且所介紹的知識并不深奧，所以[B]“研究無氧糖酵解發(fā)現(xiàn)的歷史科學家”不可能是作者針對的聽眾;本文并沒有提到解剖學方面的知識，所以[C]“專業(yè)研究比較解剖學的研究生”屬于無中生有;本文列舉恐龍的例子只是為了說明無氧性能量儲存同動物體型的大小相稱這個問題，并沒有提到其他史前動物，不可能吸引對史前動物感興趣的動物學家，所以[D]“對史前動物感興趣的動物學家”不可能是作者針對的聽眾。

　　全文譯文

　　長期以來，人們一直知道，任何動物的氧化新陳代謝率(利用氧氣將食物轉(zhuǎn)化為能量的過程)都對其生存方式有著深刻的影響。比如，小型動物的高新陳代謝率可以給它們的每個重量單位提供持續(xù)不變的力量和活力，但是，這要以不斷消耗食物和水為代價。由于大型動物的新陳代謝率相對較低，所以它們可以依賴時有時無的食物供給很好地生存，但是其每克體重生產(chǎn)的新陳代謝能量很少。1)因此，如果只考慮氧化新陳代謝率，那么人們可能認為，更小、更活躍的動物可以捕食較大型的動物，至少如果它們發(fā)動群體攻擊的話會如此;也許它們可以做到這一點，如果不是因為無氧糖酵解這個重要的補償機制的話。

　　無氧糖酵解是一個在無氧狀態(tài)下通過把肌糖原質(zhì)分解成乳酸和三磷酸腺苷(能量供應者)從而產(chǎn)生能量的過程。無氧糖酵解可以產(chǎn)生能量是糖原質(zhì)存在的作用——糖原質(zhì)大約占所有脊椎動物肌肉凈重的0.5%.因此，脊椎動物的無氧性能量儲存同其體型的大小相稱。2)比如-如果某些食肉動物攻擊了一只100噸重的恐龍。由于這類恐龍通常行動遲緩。所以它可能通過無氧糖酵解在瞬間產(chǎn)生3，000個人進行氧化新陳代謝所能產(chǎn)生的能量。這就解釋了許多大型動物是如何設(shè)法與它們周圍更活躍的動物競爭的原因：給低氧化新陳代謝率的補償就是糖酵解。

　　不過，這種補償有局限性。任何動物的糖原質(zhì)儲存最多只夠維持大約兩分鐘的最劇烈運動，之后就只剩下正常的氧化新陳代謝能量來源。3)一陣劇烈運動結(jié)束后，體液中乳酸的含量就會高，這使得大型動物容易受到攻擊，直到乳酸通過氧化新陳代謝由肝臟再次轉(zhuǎn)化成葡萄糖，然后，葡萄糖(部分)被送回到肌肉進行糖原質(zhì)的再合成。在這個過程中，動物由于無氧糖酵解所導致的大量能量消耗必須得到補償——按比例來說，較大脊椎動物的這種消耗比較小動物大得多。比如，小地鼠在幾分鐘內(nèi)就能補償其最劇烈運動所消耗的糖原質(zhì)，但是體型龐大的恐龍卻需要三個多星期才能完成補償。似乎可能的是，大型脊椎動物這種冗長的補償時間被證明對其生存非常不利。幸運的是，只有在需要時才會使用肌糖原質(zhì)，盡管那樣，也只有在需要一定量的糖原質(zhì)時才如此。只有在驚恐或者生死搏斗時，所有的能量儲備才會被消耗。As you read this， nearly 80，000 Americans are waiting for a new heart， kidney or some other organ that could save their life. Tragically， about 6，000 of them will die this year——nearly twice as many people as perished in the Sept. 11 attacks——because they won't get their transplant in time. The vast majority of Americans (86%， according to one poll) say they support organ donation. But only 20% actually sign up to do it. Why the shortfall?

　　Part of the problem is the way we handle organ donations. Americans who want to make this sort of gift have to opt in——that is， indicate on a driver's license that when they die， they want their organs to be made available. Many European and Asian countries take the opposite approach; in Singapore， for example， all residents receive a letter when they come of age informing them that their organs may be harvested unless they explicitly object. In Belgium， which adopted a similar presumed-consent system 12 years ago， less than 2% of the population has decided to opt out.

　　Further complicating the situation in the U.S. is the fact that whatever decision you make can be overruled by your family. The final say is left to your surviving relatives， who must make up their minds in the critical hours after brain death has been declared. There are as many as 50 body parts， from your skin to your corneas， that can save or transform the life of a potential recipient， but for many families lost in grief， the idea of dismembering a loved one is more than they can bear.

　　The U.S.， like all medically advanced societies， has struggled to find a way to balance an individual's rightful sovereignty over his or her body with society's need to save its members from avoidable deaths. Given America's tradition of rugged individualism and native distrust of Big Brotherly interference， it's not surprising that voters resisted attempts to switch to a presumed-consent system when it was proposed in California， Oregon， Minnesota， Pennsylvania and Maryland. Health Secretary Tommy Thompson last spring announced plans for a new initiative to encourage donations——including clearer consent forms——but its impact is expected to be modest. Given the crying need for organs， perhaps it's time we considered shifting to something closer to the presumed-consent model.

　　Meanwhile， if you want to ensure that your organs are donated when you die， you should say so in a living will or fill out a Uniform Donor Card (available from the American Medical Association)。 Make sure your closest relatives know about it. And if you don't want to donate an organ， you should make your wishes equally explicit.

　　注(1)：本文選自Time; 12/10/2001， p117;

　　注(2)：本文習題命題模仿對象2003年真題text 3;

　　1. According to the author， one of the reasons for a shortage of organs in America is ______.

　　[A] most Americans are reluctant to donate their organs after death

　　[B] the information about organ donation is not popular in America

　　[C] the ways to handle organ donation is far from perfect

　　[D] people waiting for transplant are rapidly increasing in America

　　2. What is most Americans‘ attitude towards the organ donation?

　　[A] Indifferent.

　　[B] Indignant.

　　[C] Detached.

　　[D] Supportive.

　　3. It can be inferred from paragraph 4 that ______.

　　[A] Americans have a long tradition of weak individualism

　　[B] all the states in America resist the presumed-consent system

　　[C] it‘s not easy to find a way to serve the society’s need and at the same time to protect the individual‘s right in the matter of organ donation

　　[D] the government is not active in solving the problem

　　4. The term “presumed-consent” probably means ______.

　　[A] one‘s organs should be donated whether they agree or not

　　[B] one is supposed to agree that their organ will be donated after death unless they explicitly object

　　[C] dismembering a dead body is inhuman

　　[D] one is assumed to be happy after they decide to donate their organs

　　5. From the text， we can see the author‘s attitude towards organ donation is ______.

　　[A] supportive

　　[B] indignant

　　[C] indifferent

　　[D] negative

　　答案：CDCBAPlowing through the New York Times on a recent Sunday， I read in the Metro Section that infertile couples in the market for smart-kid genes regularly place advertisements in the newspapers of their own Ivy League alma maters offering female undergraduates $7，500 for a donated egg. Before I could get that news comfortably digested， I came across an article in the Magazine section describing SAT prep courses for which parents spend thousands in the hope of raising their child's test scores enough to make admission to an Ivy League college possible. So how can people who have found a potential egg donor at an Ivy League college tell whether the donor carries genuine smart-kid genes or just pushy-parents genes?

　　The donor herself may not even be aware that such a distinction exists. After years of expensive private schooling and math tutors and tennis camps and SAT prep courses and letters of recommendation from important family friends， she's been told that， unlike beneficiaries of affirmative action， she got into an Ivy League college on pure merit.

　　Since it is probably safe to assume that people intent on securing high-priced Ivy League eggs are carrying some pushy-parents genes themselves， their joining forces with a donor who got into an Ivy League college by dint of her family's willingness to fork over 10 grand to an SAT prep course could result in a child with somewhere between a dose and a half and 2 1/2 doses of pushy-parents genes. Apparently the egg seekers aren't troubled by the prospect of having their grandchildren raised by this sort of person.

　　If you have any doubts about whether the dosages I cite are based on a thorough grounding in genetics and statistics and advanced microbiology， rest assured that I attended an Ivy League college myself. That was in the days， I'll admit， when any number of people were admitted to such institutions without having shown any evidence of carrying smart-kid genes even in trace elements. Somehow， most of these dimmer bulbs managed to graduate——every class needs a lower third in order to have an upper two-thirds——and somehow most of them are now millionaires on Wall Street.

　　One element many of them had going for them in the admissions process was that they were identified as “l(fā)egacies”——the offspring of alumni. In Ivy League colleges， alumni children are even now admitted at twice the rate of other applicants. For that reason， egg seekers may not actually need genuine smart-kid genes for their children： after all， an applicant whose mother and father and egg donor were all alumni could be considered a triple legacy.

　　But how about the college-admission prospects of the grandchildren? As methods are perfected of enhancing a college application through increasingly expensive services——one young man mentioned in the magazine article had $25，000 worth of SAT preparation——it might become more important to have a parent who's a Wall Street millionaire than to have smart-kid genes. Maybe it would be prudent to add a sentence to those ads in college papers： “Preference given to respondents in the lower third of the class.”

　　注(1)：本文選自Time;01/25/99， p20;

　　注(2)：本文習題命題模仿對象為：1、2、3題模仿2000年真題text4 1-3題;4、5題分別模仿1999年真題text1第4題和text4第4題;

　　1. In the author‘s eyes， a female student from an Ivy League college is__________.

　　[A] an ideal egg donor

　　[B] not necessarily an intelligent person

　　[C] more influenced by her parents than by anything else

　　[D] more likely to carry smart-kid genes

　　2. According to the author， what may chiefly be the reason for the donor‘s admission in an

　　Ivy League college?

　　[A] her own merits

　　[B] the affirmative action

　　[C] her smart-kid genes

　　[D] her parents‘ efforts

　　3. Which of the following is true according to the author?

　　[A] American parents would send their children into an Ivy League college at any cost

　　[B] Ivy League colleges used to admit students who showed no sign of intelligence

　　[C] alumni children stand a better chance to be admitted than other applicants

　　[D]egg-seekers care nothing about the pushy-parents genes

　　4. The author‘s attitude towards the issue seems to be ____________.

　　[A] approving

　　[B] objective

　　[C] indifferent

　　[D] ironic

　　5. It could be inferred from the text that____________.

　　[A] wealth is more important than intelligence in application for Ivy League colleges

　　[B] Ivy League colleges are increasingly expensive

　　[C] egg-seekers can get better genes from millionaires

　　[D] the prospects of college-admission are gloomy

　　答案：B D C D AThe once radical notion that birds descended from dinosaurs——or may even be dinosaurs， the only living branch of the family that ruled the earth eons ago——has got stronger and stronger since paleontologists first started taking it seriously a couple of decades ago. Remarkable similarities in bone structure between dinos and birds were the first clue. Then came evidence， thanks to a series of astonishing discoveries in China's Liaoning province over the past five years， that some dinosaurs may have borne feathers. But a few scientists still argued that the link was weak; the bone similarities could be a coincidence， they said. And maybe those primitive structures visible in some fossils were feathers——but maybe not. You had to use your imagination to see them.

　　Not anymore. A spectacularly preserved fossil of a juvenile dinosaur， announced by a team of paleontologists from the Chinese Academy of Geological Sciences and New York City's American Museum of Natural History in the latest issue of Nature， is about as good a missing link as anyone could want. “It has things that are undeniably feathers，” exults Richard Prum， of the University of Kansas Natural History Museum， an expert on the evolution of feathers. “But it is clearly a small， vicious theropod similar to the velociraptors that chased the kids around the kitchen in Jurassic Park.”

　　The find helps cement the dinosaur-bird connection， but it also casts new light on the mystery of why nature invented feathers in the first place. For the better part of a century， biologists have assumed that these specialized structures evolved for flight， but that's clearly not true. “The feathers on these dinosaurs aren't flight-worthy， and the animals couldn't fly，” says paleontologist Kevin Padian， of the University of California， Berkeley. “They're too big， and they don't have wings.” So what was the original purpose of feathers? Nobody knows for sure; they might have been useful for keeping dinos dry， distracting predators or attracting mates， as peacocks do today.

　　But many biologists suspect that feathers originally arose to keep dinosaurs warm. The bone structure of dinosaurs shows that， unlike modern reptiles， they grew as fast as birds and mammals——which dovetails with a growing body of evidence that dinos were， in fact， warm-blooded. Says Padian： “They must have had a high basal metabolic rate to grow that fast. And I wouldn't be surprised if they had some sort of skin covering for insulation when they were small.” Says Norell： “Even baby tyrannosaurs probably looked like this one.”

　　At the rate feathered dinosaurs are turning up， it shouldn't take long to solidify scientists' understanding of precisely how and why feathers first arose and when the first birdlike creature realized they were useful for flight. Meanwhile， kids had better get used to the idea that T. rex may have started life looking an awful lot like Tweety Bird.

　　注：(1)本文選自New York Times;05/07/2001， p56， 2p， 1 map， 2c

　　注：(2)本文習題命題模仿對象1999年真題text2(1、2、3、5)和text4第3題(4)

　　1. We learn from the beginning of the passage that ________________.

　　[A] scientists are split as to whether birds descended from dinosaurs

　　[B] the bone similarities between birds and dinosaurs are a coincidence

　　[C] fossils have proven that birds evolved from dinosaurs

　　[D] the idea that birds are connected with dinosaurs has always been taken seriously

　　2. Speaking of the recently-announced fossil of a juvenile dinosaur， the author implies that ______.

　　[A] it shows vividly how dinosaur flies

　　[B] it brings new mystery to paleontologists

　　[C] it further proves the link between birds and dinosaurs

　　[D] it solves the puzzle of birds‘ evolution

　　3. In the view of Kevin Padian， the feathers on those dinosaurs ____________.

　　[A] were of no practical value

　　[B] were useful for flight

　　[C] could protect dinosaurs from their natural enemy

　　[D] were good for insulation

　　4. The original purpose of feather was___________.

　　[A] to help dinosaurs fly

　　[B] to keep dinosaurs warm

　　[C] to distract predators

　　[D] a mystery

　　5. We learn from the last paragraph that __________.

　　[A] a baby dinosaur looks like a bird

　　[B] T-rex is a kind of dinosaur figure familiar to kids

　　[C] living feathered dinosaurs can still be found in certain parts of the world

　　[D] scientists understand precisely how and why feathers first arose

　　答案：A C D D BIf you wanted to question whether global warming is indeed upon us， last week was not the time to do it. Two weeks before the official beginning of summer， a heat wave baked the eastern third of the U.S. and Canada， driving temperatures high into the 90s and even 100s. At the same time， a flurry of scientific papers was released that seemed to explain all the late-spring suffering. In one study， French researchers reported that heat-trapping greenhouse gases are at their highest levels in 420，000 years. In another， U.S. scientists found that 57 species of butterfly may be altering their migratory patterns in response to changing heat patterns.

　　In light of all this， a sweltering public must have been convinced at last that it's time to do something to cool off the overheated planet， right? Wrong. Even as the temperature was climbing， a new survey by the American Geophysical Union found that Americans are less concerned than ever about combatting global warming. “The more we talk about warming，” says the study's director， John Immerwahr， “the [more the] public's concern goes down.”

　　Such an environmental disconnect may not be much of a mystery. Environmentalists complain that over the past two years industry groups have launched a coordinated advertising campaign to torpedo the 1997 Kyoto treaty， which requires industrial nations to reduce greenhouse emissions. More than $13 million has been spent on ads to block ratification of the treaty by the U.S. Senate. “The purpose of the ads was to convince most Americans that there isn't a problem or that it's too expensive to fix，” says National Environmental Trust spokesman Peter Kelly.

　　Environmentalists also criticize President Clinton for what they believe is his failure to press the issue. Only last week， Clinton moved for Kyoto treaty changes that environmental groups see as industry-pleasing loopholes. Says Daniel Weiss， the Sierra Club's political director： “Timid leaders communicate hopelessness.” And hopelessness breeds indifference. If such popular so-whating persists， Immerwahr warns， the public may begin grasping at phony solutions to global warming. At the end of last week， some people took comfort from the report of a vast haze of pollutants that collects over the Indian Ocean in the winter， but that researchers only recently studied. Filthy as the cloud is， it does deflect solar radiation， and that could lead to cooling. But scientists warn that we cannot simply pollute our way out of global warming. The soot drops from the hazy atmosphere in weeks， whereas greenhouse gases remain for centuries.

　　The way out of this gridlock， environmentalists say， is to show it's possible to reduce greenhouse gases without sinking the economy. Solutions include cleaner cars and better wind- and solar-power technologies. Says Greg Wetstone， program director for the Natural Resources Defense Council： “When these kinds of options become available， people will feel less hopeless.” Of course， it's also possible that only when people feel less hopeless will they press their leaders to make the solutions available.

　　注(1)：本文選自Time;06/21/99， p62， 3/4p， 2c.

　　注(2)：本文習題命題模仿對象1998年text2和1997年text3第4題

　　1. According to the author， global warming is ___________.

　　[A] causing a lot of trouble

　　[B] not as serious as it seems

　　[C] felt only in America and Canada

　　[D] what accounts for the high level of greenhouse gases

　　2. Speaking of global warming， American public is ______________.

　　[A] concerned

　　[B] indifferent

　　[C] worried

　　[D] frightened

　　3. The public‘s reaction to global warming is mainly a result of _____________.

　　[A] their disbelief of the existence of such problem

　　[B] the advertising campaign of industrial groups

　　[C] the high cost of fixing the problem

　　[D] American Senate‘s disapproval of Kyoto treaty

　　4. Which of the following is NOT mentioned in the passage?

　　[A] Environmentalists urge President Clinton administration to press the issue.

　　[B] Kyoto treaty aims at curbing the global warming problem.

　　[C] American government is partly responsible for the public‘s attitude toward global warming.

　　[D] Industrial groups do not care about global warming.

　　5. It can be inferred from the passage that _____________.

　　[A] environmentalists support the idea of solving global warming through pollution

　　[B] the poor leadership of American President has produced a very bad influence

　　[C] American economy will suffer if global warming is curbed

　　[D] people have no confidence in solving problem of global warming

　　答案：A B B A BFor 30 years， Smithsonian Institution archeologist Dennis Stanford searched in vain for the origins of the first Americans. Every textbook described how mammoth-hunters from Siberia had migrated across the Bering land bridge about 12，000 years ago and had slowly wandered south and east until they filled the New World. In each of their settlements， this theory held， the original Americans left their calling cards： distinctively shaped spear points named after the site in Clovis， N.M.， where the stone tips were first unearthed. If this account was right， Stanford reasoned， then Siberia should be littered with similar points. But not a single Clovis point has turned up in Siberia. And now Stanford has a radical new proposal to explain why. Clovis people， he thinks， came from Europe——arriving 15，000 years before Columbus， and by boat. “They were from Iberia， not Siberia，” Stanford told startled colleagues at an archeology conference last month.

　　Debate over a European connection has dogged anthropology in recent months， though until now no one of Stanford's stature had stated it so un-equivocally and publicly. But the similarities between the oddly shaped stone points of Clovis and the European culture called Solutrean strongly suggest this conclusion， say Stanford and colleague Bruce Bradley. Moreover， tools recently found beneath Clovis-era layers at a dig in Cactus Hill， Va.——about where European itinerants could have first landed——also resemble Solutrean artifacts. The Solutrean theory poses similar questions to those raised by Kennewick Man， the 8，400-year-old skeleton found in Washington state in 1996 and initially called European by an anthropologist. A new federal study to help determine whether K-Man's remains should be turned over to local tribes just concluded that the body looked more Asian than European， though not Siberian. But it didn't match any modern Indian tribe， a finding that Indians see as the latest scheme to deny tribes the right to repatriate and rebury such remains.

　　Native Americans aren't the only ones dismayed by the Euro theory. Solutrean expert Lawrence Straus， an anthropology professor at the University of New Mexico， dismisses the resemblance between the spear points as an instance of two cultures' arriving at a similar idea independently. “This is a classic case of convergence，” says Straus. “And it's not even a tricky case.” Moreover， Solutrean culture ended 17，000 years ago， at least 5，000 years before the first evidence of Clovis culture. And there is no evidence that Solutreans had the requisite boats to paddle across the North Atlantic.

　　Many scientists grumble that Stanford should publish his findings in peer-reviewed journals be-fore talking in public. Stanford promises to publish soon， but in the meantime， he says， “I'm trying to get people to think more broadly.” No argument there.

　　注(1)：本文選自Newsweek; 11/15/99， p71;

　　注(2)：本文習題命題模仿對象2004年真題Text 4

　　1. What does Stanford think of the origins of the first Americans?

　　[A]He thinks that the first Americans came from Clovis， N.M.

　　[B]He agrees with the common idea that the first Americans came from Siberia.

　　[C]He thinks that the first Americans came from Europe.

　　[D]He thinks that it was people from Iberia who first invented the boat and came to America.

　　2. We can learn from the text that Indian tribes regard the results of the federal study as _______.

　　[A]a tricky scheme

　　[B]convincing enough

　　[C]a cute trap

　　[D]unreasonable

　　3. The views of Lawrence Straus and Stanford are _________.

　　[A]identical

　　[B]similar

　　[C]complementary

　　[D]opposite

　　4. According to Lawrence Straus， the spear points __________.

　　[A]show the products makers came from the same culture

　　[B]do not show any connection between the two cultures

　　[C]are not the products of the different inhabitants

　　[D]show the resemblance of the two different cultures

　　5. Which of the following statement is true?

　　[A]K-Man's remains helped to certify Stanford‘s assertion.

　　[B]The first Americans came from Europe by boat.

　　[C]Anthropologists fail to make such a certain statement as Stanford.

　　[D]It was the Indian tribes‘ rights to rebury the K-Man's remains.

　　答案：CADBCThe basic workings of DNA and RNA are no mystery. It's now well known that DNA consists of four nucleotide “bases” (A， T， C and G)， whose linear sequences (AATAGGCTCC……) encode hereditary information. Genes——discrete segments of long DNA molecules——transcribe their sequences onto single-strand messenger RNA molecules， which then serve as templates for proteins. In short， DNA makes messenger RNA， and messenger RNA makes proteins. The production of a particular protein is the goal of each gene. This 50-year-old insight is the bedrock of modern biology， but science has not fully solved a related mystery. If every cell in an organism contains the same full complement of genes， why are the cells themselves so varied? How do different genes get turned on (“expressed”) or off (“silenced”) in just the right combinations to produce heart cells， bone cells and brain cells?

　　That's where microRNA enters the picture. In the early 1990s， researchers studying a species of worm discovered genes for a very short and very unusual piece of RNA. Instead of synthesizing proteins， this tiny RNA molecule latched onto messenger RNAs (chart)， causing their destruction. Without messenger RNA， no protein was produced. In effect， the gene for that protein had been silenced. The discovery was initially dismissed as an oddity in a worm， but scientists have since found genes for hundreds of microRNAs in various plants and animals——200 in humans alone. Many of these genes have survived in identical forms in different species， indicating that they are essential to life. What， exactly， is their role? We now suspect that by silencing particular genes at just the right times——a process called RNA interference——they push genetically identical cells down different paths of development， enabling some to digest food while others perceive light.

　　RNA interference gives researchers a new tool for understanding how living things grow——how a plant assumes a particular shape， for example， or how a baby's hand forms during gestation. Moreover， because microRNAs are so small and simple in structure， they can be manufactured for use as research tools. If scientists suspect that a particular gene is responsible for a disease， they can design microRNA to silence the gene in affected laboratory animals. If the disease is prevented or cured， the gene becomes a target for treatment.

　　RNA interference has yet to generate new medicines， but if the technique fulfills its promise， it could help us treat everything from viral infections to cancer. MicroRNAs could be used to seal off human cells from disease-causing viruses， or to disable viruses that gain entry. In a recent test-tube study， researchers showed that RNA interference could make cells impermeable to HIV. Early studies suggest that microRNAs can also boost the production of stem cells in culture. By blocking production of growth-promoting proteins， microRNAs may even help contain cancer cells.

　　It is one thing to manipulate cells in a test tube， quite another to treat people. Getting microRNAs safely into the right cells in the body will be complicated. No one has yet attempted a human experiment. Even so， a field that was just a curiosity in 1993 is now poised to change the world——all because we invested in basic research. The scientists who discovered microRNAs were not trying to prevent AIDS， grow stem cells or treat cancer. They just wanted to figure out how something happened in a worm. As Buckminster Fuller observed， “Development is programmable; discovery is not.”

　　注(1)：本文選自Newsweek; 12/8/2003， p96-96， 1p， 1 diagram， 1c;

　　注(2)：本文習題命題模仿對象2004年真題Text 3;

　　1. The expression “silenced”(Line 5， Paragraph 2) most probably means _________.

　　[A]ruined

　　[B]destroyed

　　[C]killed

　　[D]stopped

　　2. How does the author feel about the study of MicroRNA?

　　[A]Optimistic.

　　[B]Confused.

　　[C]Frightening.

　　[D]Shocking.

　　3. When mentioning “It is one thing to manipulate cells in a test tube， quite another to treat people.”(Line 1， Paragraph 5)， the author implies that __________.

　　[A]the test of cells and the treatment of people are unrelated to each other

　　[B]the treatment of people is more complex than the cells in the laboratory

　　[C]more emphasis should be laid on the human tests

　　[D]human treatment may not be successful

　　4. What does Buckminster Fuller mean by “Development is programmable; discovery is not.”(Last Line， Last Paragraph)?

　　[A]Discovery is always made beyond one‘s expectation.

　　[B]Development is easier than discovery.

　　[C]Development lacks curiosity while discovery does not.

　　[D]Development is less important than discovery.

　　5.Which of the following is not true about RNA interference?

　　[A]It prevents disease-causing viruses from entering human body.

　　[B]It improves the production of stem cells.

　　[C]It can cure of all kinds of human diseases.

　　[D]It silences certain protein to prevent tumor.

　　答案：DABACHalf the game is 90 percent mental，“ Yogi Berra once said， or something like that， and science is now getting around to putting his aphorism to the test. Researchers including Debbie Crews of Arizona State University and John Milton of the University of Chicago have been studying patterns of brain activation——not in baseball players but in golfers， who make better subjects because they don't move around as much and the electrodes stay stuck to their heads. Yogi might have been surprised by the researchers' conclusion， though： the better the golfer， the less brain activity he shows in the seconds before he makes his shot.

　　Crews， a sports psychologist who studies putting——even the minimal agitation of a chip shot can upset her experimental apparatus——has found that a key difference between amateurs and pros lies in the left hemisphere. This is the seat of logic， analysis， verbal reasoning and the kinds of thoughts——Maybe I should just kind of squinch over a little more to the left——that you never imagine crossing Tiger Woods's mind. Professionals， once they've determined how to make a shot， follow an invariable routine that renders conscious thought unnecessary. “How you think is probably more important than what you think，” Crews says. “Quieting the left hemisphere is really critical.”

　　Or， to put it another way， when Milton asked some LPGA golfers what they thought about just before taking a shot， they answered： nothing. To test this， he rounded up a half-dozen pros and an equal number of amateurs and had them imagine making a specific shot——a wedge shot of 100 yards to the green， with no wind——while monitoring their brains in a functional magnetic resonance imaging machine. “The professionals are just much more specialized and efficient，” Milton says. “You put in a quarter and you get your shot.” The amateurs， by contrast， showed more total brain activation， involving more areas of the brain. In particular， amateurs activated the basal ganglia——involved in learning motor functions——and the basal forebrain and amygdala， responsible for， among other functions， emotions. “They're not fearful or anxious，” Milton says， “but they get overwhelmed by details， by the memories of all the shots they've missed in the past.” Some of his subjects worried about hitting the ball into the water， which was curious， because he hadn't even mentioned a water hazard in describing the imaginary shot to them.

　　Professional athletes， as a rule， know how to keep focus， although there are exceptions， like Chuck Knoblauch， the Yankee second baseman who suddenly lost the ability to make a routine throw to first base. Milton is already trying to apply these lessons to stroke and other rehabilitation patients who have to relearn skills like walking; he recommends putting more emphasis on visualization and improving mental focus. In many aspects of life， it seems， half the game really is 90 percent mental.

　　注(1)：本文選自Newsweek; 6/2/2003， p14;

　　注(2)：本文習題命題模仿對象2004年真題Text 4(個別題目順序加以調(diào)整);

　　1. The views of Yogi Berra and researchers including Crews and Milton are ________.

　　[A]similar

　　[B]identical

　　[C]opposite

　　[D]complementary

　　2. We can learn from the text that the difference between pros and amateurs lies in

　　_______.

　　[A]the activity of the left hemisphere

　　[B]the way of their thinking

　　[C]the ability to control one‘s brain

　　[D]the ability to forget the past failures

　　3. Tiger Woods， according to the text， is probably ________.

　　[A]a professional golf player

　　[B]a professional baseball player

　　[C]a sports psychologist

　　[D]a researcher

　　4. What is the key to the success of golfers according to the text?

　　[A]Not to think of anything related to your past losses.

　　[B]To be more specialized and efficient.

　　[C]Try to activate your whole brain.

　　[D]Quiet your left hemisphere and think of nothing.

　　5. What can we learn from the last paragraph?

　　[A]What the researchers have found proves Yogi Berra‘s words.

　　[B]Baseball player should do as Yogi Berra said.

　　[C]Mentality plays a very important role in many aspects of life.

　　[D]Sports and medicine share some common principles.

　　答案：CADBCThe sun is not growing weaker， yet its light appears to be dimming. Between 1960 and 1990， some scientists believe， the amount of solar radiation reaching Earth's surface may have declined as much as 10%——and in some places， Hong Kong， for example， more than 35%.

　　What was going on? Well， it appears that increased air pollution during those 30 years——over Asia， in particular——with the help， perhaps， of some increased cloudiness， may have exerted a cooling influence on the surface of the planet even as carbon dioxide and other greenhouse gases were encouraging the atmosphere to warm. The impacts of that tug-of-war on the climate system could be devilishly difficult to untangle. At the same time， no task could be more urgent. For if global pollution has helped keep global warming in check， says Veerabhadran Ramanathan， an atmospheric scientist at the University of California at San Diego， then the full impact of the buildup of greenhouse gases has yet to be felt. This week， at the American Geophysical Union meeting in Montreal， Ramanathan and others will be presenting the latest data on the solar-dimming problem and pondering its implications for the climate system as a whole.

　　Many scenarios for global warming， for example， invoke a speedup in the hydrological cycle by which water evaporates and then comes down as rain. The cooling produced by solar dimming， however， may slow the rate of evaporation， while higher up in the atmosphere the pollutants responsible for absorbing and reflecting sunlight are likely to interfere with the process that produces rain.

　　Why? These pollutants， which take the form of tiny， airborne particles called aerosols， act as nuclei around which cloud droplets form. The problem is， there are too many aerosols in the atmosphere competing for water molecules， so the cloud droplets that form are too small and never become weighty enough to fall to the ground. As a result， says Beate Liepert， an atmospheric physicist at Columbia University's Lamont-Doherty Earth Observatory， the atmosphere could be filled with moisture while Earth's surface thirsts for rain.

　　Many questions remain， including the true extent of the dimming. One analysis pegs the average worldwide darkening to be about 4% over three decades， while another computes it to be more than twice that much. There are also questions about the reliability of the devices that measure the sunlight reaching Earth's surface. Known as radiometers， these instruments are nothing more than flat， black solar collectors capped with glass. They are sometimes finicky; a smudge of dirt or a speck of dust can cause bogus readings and change the calculated results.

　　Solar dimming， in other words， is a problem still in the process of being defined， and as its dimensions become clearer， so will the nature of the challenge the world faces. Although scientists have done a lot of thinking about global warming， they are just beginning to grapple with the problem of how global warming and solar dimming interact. As Ramanathan puts it， “It's like we have a new gorilla sitting down at the table”——and it could turn out to be a very big gorilla indeed.

　　注(1)：本文選自Time; 5/24/2004， p60-60， 2/3p;

　　注(2)：本文習題命題模仿對象2004年真題Text 3;

　　1. By “tug-of-war”(Line 4， Paragraph 2)， the author means _________.

　　[A]the different effect of solar dimming and global warming

　　[B]the impact of the solar dimming on the climate system

　　[C]the influence of the solar dimming on the global warming

　　[D]the interaction between the solar dimming and global warming

　　2. How do the scientists feel about the current climate situation?

　　[A]Serious.

　　[B]Optimistic.

　　[C]Carefree.

　　[D]Panicked.