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四、重点归纳题练习 |
例1 That the application of new technology can increase the productivity of existing coal mines is demonstrated by the case of Tribnia's coal industry. Coal output per miner in Tribnia is double what it was five years ago, even though no new mines have opened.
Which of the following can be properly concluded from the statement about coal output per miner in the passage?
A. If the number of miners working in Tribnian coal mines has remained constant in the past five years, Tribnia's total coal production has doubled in that period of time.
B. Any individual Tribnian coal mine that achieved an increase in overall output in the past five years has also experienced an increase in output per miner.
C. If any new coal mines had opened in Tribnia in the past five years, then the increase in output per miner would have been even greater than it actually was.
D. If any individual Tribnian coal mine has not increased its output per miner in the past five years, then that mine's overall output has declined or remained constant.
E. In Tribnia the cost of producing a given quantity of coal has declined over the past five years.
解析： 原文两件事：（1）科技可提高产量。（2）在没有新矿开采的情况下，人均产量翻倍。
归纳题中，总结出原文的事件之后，先思考下通过这些事件可否推测出结论的方向。
A项：人均产量×总工作时间×矿的数量＝总产量，因此A项正确。
B项：科技因素可提高产量，但并不是只有科技因素会让产量上升，也可以有其他因素，比如矿工人数增加，因此B项不正确。
C项：新矿出现会让总产量上升，但并不影响人均产量。“人均产量×总工作时间×矿的数量＝总产量”，第三个因素上升或下降只能影响总产量，并不能影响第一个因素。因此，C项不正确。
D项：其他因素也会导致总产量变化，比如矿工人数，故D选项错误。
E项：“生产煤的成本”在原文中未提及，所以排除此项。
例2 Although most smoking-related illnesses are caused by inhaling the tar in tobacco smoke, it is addiction to nicotine that prevents most smokers from quitting. In an effort to decrease the incidence of smoking-related illnesses, lawmakers in Sandonia plan to reduce the average quantity of nicotine per cigarette by half over the next five years. Unfortunately, smokers who are already addicted to nicotine tend to react to such reductions by smoking correspondingly more cigarettes.
The information above most strongly supports which of the following predictions about the effects of implementing the Sandonian government's plan?
A. The average quantity of tar inhaled by Sandonian smokers who are currently addicted to nicotine will probably not decrease during the next five years.
B. Sandonian smokers who are not already addicted to nicotine will probably also begin to smoke more cigarettes during the next five years than they had previously.
C. The annual number of Sandonian smokers developing smoking-related illnesses will probably decrease during the next five years.
D. The proportion of Sandonians attempting to quit smoking who succeed in that attempt will probably decrease during the next five years.
E. The number of Sandonians who quit smoking during the next five years will probably exceed the number who quit during the last five years.
解析： 题目问上文会支持哪个预测，既然是“预测”，就不追求答案百分之百地可被推出，找一个最可能正确的选项即可。
原文描述的事件：（1）尼古丁让人戒不了烟。（2）计划把烟的尼古丁含量减半。（3）人们抽更多的烟。
A项：通过“人们抽更多的烟”是否一定能推出尼古丁吸入量和过去一样呢？显然不能，因为我们不知道抽的烟是否增加了一倍。只有抽烟频率增加一倍，结合单支烟尼古丁含量减半，才能推出吸入的尼古丁量和过去一样。但是此题不追求一定推出，因此A项待选。
B项：文章中讲述的是“已经对尼古丁上瘾的人群”，此项描述的不属于此范围，肯定不正确。
C项：第三件事情告诉我们抽烟的人依然会抽非常多的烟，这和患病人数会下降是反方向，故排除此项。
D项：从“吸烟的人会抽更多的烟”，无法推出人们会戒烟。同理，E项也不可推出。
得出答案为A。
例3 A medieval manuscript called L contains all eighteen extant tragedies by the Greek playwright Euripides. Of these, ten called the “select plays,”are accompanied in L by ancient commentaries and also appear in other medieval manuscripts; this group includes some of Euripides' best-known works, including the Medea . The other eight, which appear only in L, appear in alphabetical order, without commentary. The Electra is one of the alphabeticals.
Which of the following can be reliably concluded on the basis of the statements given?
A. Only Euripides' best-known works are accompanied by ancient commentaries in extant medieval manuscripts.
B. The select plays are accompanied by ancient commentaries because they were the best known of Euripides' works.
C. No commentaries were written about Euripides' Electra in ancient times.
D. Euripides' Medea never appears in medieval manuscripts unaccompanied by ancient commentary.
E. Euripides' Electra does not appear accompanied by a commentary in any extant medieval manuscript.
解析： 此题考查的是考生对事件范围的归纳能力。归纳题的答案一般不包括绝对化内容，除非原文中出现了绝对化概念。我们不可能概括总结出一个原文中没有提到的极端程度词。原文中如果出现最高级等描述程度词汇，必须记住这些绝对化内容。因此，我们在概括事件之后，可再总结下事件的范围。
原文可记成：（1）L包括18个文件。（2）10个带评论，在其他手卷中也出现，Medea是其一。（3）另外8个只有在L里面出现，没有评论，Electra是其一。
A项：第二件事情描述10个带评论的里面包括一些很有名的作品（some of the best known works），表明还有其他带评论的作品不广为人知，因此A项很明显错误。
B项：写评论的理由无法得知，排除此项。
C项：我们只知道在手卷（manuscript）里面没有对Electra的评论，没有看到评论不代表评论一定没有写过。因此C项的逻辑不严谨。
D项：第二件事情讲Medea在其他手卷里面出现，那么在其他手卷里面出现时是否有评论，无法得知，故D错误。
E项：因为Electra只在L里面出现，所以原文中描述的第三件事情表明Electra没有评论就是表示在任何手卷中都没有评论。此项正确。
例4 The quality of unrefined olive oil is not actually defined in terms of acidity, yet extensive tests have shown that the less free oleic acid an unrefined olive oil contains per liter, the higher its quality. The proportion of free oleic acid that an olive oil contains is an accurate measure of the oil's acidity.
If the statements above are all true, which of the following conclusions is best supported by them?
A. When an olive oil is refined, the concentration of oleic acid in the oil is reduced.
B. The quality of an unrefined olive oil can be determined only by accurately measuring its acidity.
C. If an unrefined olive oil is intermediate in acidity between two other unrefined olive oils, it will also be intermediate between them in quality.
D. Free oleic acid is the only acid that unrefined olive oil contains.
E. People who judge the quality of unrefined olive oils actually judge those oils by their acidity, which the judges can taste.
解析： 文章主要在描述“酸度与油质之间的关系”。
A项：上文只告诉我们未精炼（unrefined）的油的情况，精炼后会有什么变化是无法通过常识推理的，所以此项不正确。
B项：原文中没有出现过的动词、形容词、副词、名词和绝对化词汇出现在选项中，则该选项不正确。绝对化词汇包含形容词最高级、only、solely、merely等。此项出现了原文没有的绝对化词汇only，不正确。
C项：描述了“酸度与质量的关系”，此项暂没发现错误。
D项：出现绝对化词汇only，排除。
E项：前半句没问题，逗号之后表示这样的“酸度可以尝出来”，酸度的测量方式我们无法得知，非常可能是仪器测试得出，并不能尝出来。不选E项。
得出C项为正确答案。
整个GRE考试都是挑错的过程，如果我们发现某选项挑不出错误，就先放着此项，再与其他也挑不出错误的选项进行比较。这就是“批判性思维”在考试中的运用。
