三、各种题型的举例和分析

1.填空题

Garnet and RenCo each provide health care for their employees. Garnet pays for both testing of its employees' cholesterol levels and treatment of high cholesterol. This policy saves Garnet money, since high cholesterol left untreated for many years leads to conditions that require very expensive treatment. However, RenCo does not have the same financial incentive to adopt such a policy, because ____.

A. early treatment of high cholesterol does not entirely eliminate the possibility of a stroke later in life

B. the mass media regularly feature stories encouraging people to maintain diets that are low in cholesterol

C. RenCo has significantly more employees than Garnet has

D. RenCo's employees are unlikely to have higher cholesterol levels than Garnet's employees

E. the average length of time an employee stays with RenCo is less than it is with Garnet

解析： 此题相当于解释题，即寻找Renco没有经济动机采取省钱措施的原因。

此题论证过程是：Renco和Garnet有共同点。（句1：两个公司都提供医疗保健，表示两个公司都会为员工报销医药费）Garnet公司会为员工检测胆固醇水平并提供相应治疗，因为长期来看会为公司省钱（high cholesterol left untreated for many years leads to conditions that require very expensive treatment），所以RenCo公司应该也采取同样的措施。RenCo公司没有采纳的理由是什么？找一个表达不采取策略理由的选项。

推理链题答案基本就在推理链的范围中，如果选项所描述的事件和文章论证过程中某一个事情有关联，则这个选项就和正确答案沾边，可留下备选。

A选项描述的早期治疗不可完全消除中风，但只要能省钱RenCo公司依然可以采纳文中所说的措施，为什么没有采纳？A项没说，因此此项无关。

B项讲媒体鼓励人们采纳低胆固醇的饮食。为什么有一个可省钱的措施，RenCo公司不去采纳？此项依然没有描述，此项无关。

C项表示RenCo公司人更多。如果人更多，RenCo会承担更多的医疗费用。此项不能选。

D项描述RenCo公司员工的胆固醇指标不可能比Garnet公司员工的更高。分析D项之前，大家先想一个问题：GRE既然考查逻辑，那GRE逻辑题会不会有一些违反常识的原文或答案？GRE逻辑需要进行由前提至结论的推理，这个推理如何去理解？用背景推理还是用经验推理？这里先不予解答，在后文详细说到推理链题型解法的时候，再深入描述。暂且先放着D选项，因为肯定有学生这么认为：RenCo公司员工胆固醇不会更高，所以RenCo没有采纳这措施的动机。

原文中说“高的胆固醇如果不治疗，数年的话会导致公司昂贵的医疗费用”，E项的“average length of time”（平均工作时间）与原文中的“数年”属于有话题沾边，故E项和原文有联系，选E。

2.支持题

Studies in restaurants show that the tips left by customers who pay their bill in cash tend to be larger when the bill is presented on a tray that bears a credit-card logo. Consumer psychologists hypothesize that simply seeing a credit-card logo makes many credit-card holders willing to spend more because it reminds them that their spending power exceeds the cash they have immediately available.

Which of the following, if true, most strongly supports the psychologists' interpretation of the studies?

A. The effect noted in the studies is not limited to patrons who have credit cards.

B. Patrons who are under financial pressure from their credit-card obligations tend to tip less when presented with a restaurant bill on a tray with credit-card logo than when the tray has no logo.

C. In virtually all of the cases in the studies, the patrons who paid bills in cash did not possess credit cards.

D. In general, restaurant patrons who pay their bills in cash leave larger tips than do those who pay by credit card.

E. The percentage of restaurant bills paid with given brand of credit card increases when that credit card's logo is displayed on the tray with which the bill is prepared.

解析： 题目问支持心理学家解释（psychologists' interpretation）的选项是哪个，所以看原文的时候解释本身和针对的问题要读清楚。（答题技巧：题目问什么，就回答什么）

原文先说了一个现象：如果盘子上有一个信用卡标志，则小费会给得更多，后文对这个现象进行解释：因为看到信用卡标志，人们会觉得自己有更大的购买力。要选一个能支持这种解释的选项。

此题是典型的果因推理，要找出支持原文所描述现象的原因，一种方式是排除其他可以推出这一现象的原因，即排除他因；另外一种方式是“原文的理由”可推出“原文的现象”，这样相当于把原文的推理链再描述一次，达到支持的作用。类似的角度可以是给出一个其他场合的例子或理论来解释文中现象。出题机构往往会以“给出他因”的方式进行出题，因为如果是第二种方式，那选项必须把文章中所说的现象和解释在一个选项中都提到，这样的出题方式太容易让学生觉得该选项是沾边选项。因此，此题的答案方向是：如果选项说了一个新事件，而这新事件不能推出文章中所说的现象，则无关，因为不属于排除他因；要么一个选项把原文中的现象和原因再说一次。

A项：说了新事件，此新事件又不能推出“给小费更多”这个现象，则A项无关。

B项：提了信用卡和给小费多少之间的关系，属于原文推理链的范围，先放着此项。

C项：是否拥有信用卡和信用卡标志会刺激购买力是两件事情，所以有没有信用卡和是否被刺激是两回事。

D项：本题要找的选项应能支持看到信用卡标志和给更多小费这一说法，此项即使沾边也逻辑方向相反，不选。

E项：特例可以允许任何情况发生，但是特例没有代表性（not representative），只有大多数的、可以代表某个集体的样本才能说明问题，此项的特定品牌（given brand）一样不能说明问题，完全可以把特定品牌当成一个特例来对待。

答案为B，属于第二种答案设计的模式。

3.归纳题

Shipping Clerk: The five specially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.

If the shipping clerk's statements are true, which of the following must also be true?

A. At least one of the shipments sent to Truax Construction last week was specially ordered.

B. At least one of last week's specially ordered shipments did not consist of building supplies.

C. At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week.

D. At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction.

E. At least one of the shipments sent to Truax Construction last week was sent out before Friday.

解析： 题目问如果船员的话正确，下面哪个选项也对。相当于哪个选项可以确定地从上文概括出来。解题过程类似阅读题，因为阅读题中正确选项也是从文章信息中总结出来的，只是归纳题的文章篇幅短于阅读题的文章。因此，正确选项不可以出现新元素、新概念，或原文中没有提到的绝对化程度等，毕竟不可能从文章中总结出文章没有提到过的信息。

短文告诉我们四件事情：（1）周四有特殊订单货物（special order shipment）发出。（2）周五发出的货物（shipment）中都是建筑材料（building supplies）。（3）周五后就不再发货物（shipment）。（4）Truax Construction收到的四批货物中有三批是建筑材料。

阅读GRE逻辑文章时，必须以事件为单位边阅读边总结文章中一共说了几件事。

在上述四件事情中，根据事件一，我们可否得知周四只发了特殊订单货物？有没有可能在周四也发出建筑材料？以及，根据事件二，我们可否得知只有周五这一天发出了建筑材料，而其他任何一天都没有发出建筑材料？当然不能。因为我们并没有看到类似only的限制词。所以，选项ABCD可以都去掉，比如B项，因为我们不知道在周四前是否有非特殊订单的货物发出，以及我们不知道特殊订单货物和建筑材料之间是否存在关联，所以没法判断B项是否正确。事件四表示有一批货物不是周五发出，而事件二告诉我们周五发出的都是建筑材料，则不是建筑材料的货品要么在周五前发出，要么在周五后发出，然后事件三告诉我们非建筑材料的货物只能在周五前发出，故只有E项正确。

4.解释题

When a new restaurant, Martin's Cafe, opened in Riverville last year, many people predicted that business at the Wildflower Inn, Riverville's only other restaurant, would suffer from the competition. Surprisingly, however, in the year since Martin's Cafe opened, the average number of meals per night served at the Wildflower Inn has increased significantly.

Which of the following, if true, most helps to explain the increase?

A. Unlike the Wildflower Inn, Martin's Cafe serves considerably more meals on weekends than it does on weekdays.

B. Most of the customers of Martin's Cafe had never dined in Riverville before this restaurant opened, and on most days Martin's Cafe attracts more customers than it can seat.

C. The profit per meal is higher, on average, for meals served at Martin's Cafe than for those served at the Wildflower Inn.

D. The Wildflower Inn is not open on Sundays, and therefore Riverville residents who choose to dine out on that day must either eat at Martin's Cafe or go to neighboring towns to eat.

E. A significant proportion of the staff at Martin's Cafe are people who formerly worked at the Wildflower Inn and were hired away by the owner of Martin's Cafe.

解析： 题干中explain一词提示此题为解释题。文章中有一个前后矛盾的事件（discrepancy），需要考生在选项中找到使结论成立的理由。因而，在解答解释题的过程中要特别关注结论是什么。

原文的事件包括：（1）Martin's Cafe开业影响Wildflower Inn的生意。（2）Wildflower Inn在Martin's Cafe开业后反而卖了更多的饭。

根据时间先后顺序，可知结论是第二个事件，需要找一个能推出“竞争对手Martin's Cafe存在的情况下，Wildflower Inn生意更好”的选项。

A项：Martin's Cafe自己与自己进行对比，属于纵比，而原文是自己和别人比，属于横比。此项直接可判定为无关项。即使考生不清楚这个技巧，此项也没有描述Martin's Cafe的存在会使Wildflower Inn生意更好的信息，故可排除此项。

B项：此项描述Martin's Cafe容纳不了所有光顾的客人，那些未能在Martin's Cafe 就餐的客人会不会去Riverville的其他餐馆即Wildflower Inn呢？基于常识来推理，当然有可能。因此，此项增加了“Wildflower Inn可以卖更多饭”的可能性，先放着可作为答案的备选。

C项：逻辑题不难，但如果考生修改了题目所问的事件或原文中描述的事件的意思，并按错误方向去找选项，尤其是读完了某个选项之后受其干扰，就容易选错。此题问的方向是“Wildflower Inn卖更多的饭”，不是问赚不赚钱，即使不赚钱但如果某项表达的是Wildflower Inn的饭卖得多不多的话题，也可以放着这个选项待选。排除C项。

D项：此项没有联系到Wildflower Inn卖饭更多的事件，只谈到了Wildflower Inn不营业的时候，人们要么去Martin's Cafe要么去附近的城镇，这项不能告诉我们为什么Wildflower Inn会卖更多的饭。

E项：员工会不会影响到营业额？答案是不确定的。选项没有联系Wildflower Inn会卖更多饭的事情，排除E项。

只有B项有点逻辑关联，得出答案为B项。

5.评价题

Community activist: If Morganville wants to keep its central shopping district healthy, it should prevent the opening of a huge SaveAll discount department store on the outskirts of Morganville. Records from other small towns show that whenever SaveAll has opened a store outside the central shopping district of a small town, within five years the town has experienced the bankruptcies of more than a quarter of the stores in the shopping district.

The answer to which of the following would be most useful for evaluating the community activist's reasoning?

A. Have community activists in other towns successfully campaigned against the opening of a SaveAll store on the outskirts of their towns?

B. Do a large percentage of the residents of Morganville currently do almost all of their shopping at stores in Morganville?

C. In towns with healthy central shopping districts, what proportion of the stores in those districts suffer bankruptcy during a typical five-year period?

D. What proportion of the employees at the SaveAll store on the outskirts of Morganville will be drawn from Morganville?

E. Do newly opened SaveAll stores ever lose money during their first five years of operation?

解析： evaluating这个词提示此题为评价题。评价题是从其他角度来论述原文中的前提可以推导出结论。

原文讨论的事件是“SaveAll开店与其他店倒闭”，选项中只有C和E两项沾边。E项中lose money和“倒闭”是一个方向，因此也可以先待选。对比选项后发现C项和原文核心事件描述得更近，故选C。

何为选项与原文事件“关系更近”？选项描述事件与原文的密切程度有以下的排列顺序：原文再现＞改写＞方向对＞无关选项。

选项描述内容与原文的事件一模一样即为“原文再现”，密切度最高。

选项描述内容是原文事件改写，或通过常识可以从选项推出原文事件的，密切度次之。

选项描述事件和原文事件是一个方向，但是推不出原文事件，密切度优于无关选项。

因此，只要选项和原文事件是一个方向，即可以先放着，没有更好的选项的时候，只能退而求其次，而不需要追求最佳选项。（GRE逻辑考查决策思维——没有最好的，只有相对更好的）

6.削弱题

Five years ago, as part of a plan to encourage citizens of Levaska to increase the amount of money they put into savings, Levaska's government introduced special savings accounts in which up to $3,000 a year can be saved with no tax due on the interest unless money is withdrawn before the account holder reaches the age of sixty-five. Millions of dollars have accumulated in the special accounts, so the government's plan is obviously working.

Which of the following, if true, most seriously weakens the argument?

A. A substantial number of Levaskans have withdrawn at least some of the money they had invested in the special accounts.

B. Workers in Levaska who already save money in long-term tax-free accounts that are offered through their workplace cannot take advantage of the special savings accounts introduced by the government.

C. The rate at which interest earned on money deposited in regular savings accounts is taxed depends on the income bracket of the account holder.

D. Many Levaskans who already had long-term savings have steadily been transferring those savings into the special accounts.

E. Many of the economists who now claim that the government's plan has been successful criticized it when it was introduced.

解析： weaken一词表明本题是削弱题，即降低前提推出结论的可能性。此题论证过程属于“通过现象得到解释”的果因推理题。此题除了果因推理的解题模式外，还可以用“通过计划达到目标”的方式解题。我们假设有这样的场景：“余翔想要变得更美，所以他决定去泰国做整容手术。”如果是这样的计划和目的，我们在生活中会如何进行反驳（削弱）呢？估计有人会讲“泰国手术技术太落后，整形后的鼻子风一吹就歪了”，这叫计划本身不能达到目标。假设计划可达到目标，可能又有人会讲“泰国做手术前后期成本和机会成本太大，余翔承受不了”，这叫计划本身不能被执行。我们再假设计划可执行，并且计划可达到目标，可能又有人会说“做完手术之后是美了，但是可能就不长胡子了，这是余翔不能承受的痛”，这叫计划有副作用。基本上，“计划达不成目标，计划不可被执行，计划有副作用”是“从计划到目标”出题套路的大多数答案模式。

此题的D选项讲大多数居民把长期存款存入特别账户（special account），因此达不成文中所描述的目标（plan to encourage citizens of Levaska to increase the amount of money they put into savings），因为转移了存款并没有增加存款。

7.句子作用题（黑体题）

Astronomer: Observations of the Shoemaker-Levi comet on its collision course with Jupiter showed that the comet broke into fragments before entering Jupiter's atmosphere in 1994, but they did not show how big those fragments were. Nevertheless, some indication of their size can be inferred from spectrographic analyses of Jupiter's outer atmosphere. After the fragments' entry, these analyses revealed unprecedented traces of sulfur. The fragments themselves almost certainly contained no sulfur, but astronomers believe that the cloud layer below Jupiter's outer atmosphere does contain sulfur. Since sulfur would have seeped into the outer atmosphere if comet fragments had penetrated this cloud layer, it is likely that some of the fragments were at least large enough to have passed through Jupiter's outer atmosphere without being burned up.

In the astronomer's argument, the two portions in boldface play which of the following roles?

A. The first is a claim that the astronomer seeks to show is true; the second acknowledges a consideration that weighs against the truth of that claim.

B. The first is a claim that the astronomer seeks to show is true; the second provides evidence in support of the truth of that claim.

C. The first and the second are each considerations advanced in support of the conclusion of the argument.

D. The first provides evidence in support of the conclusion of the argument; the second is that conclusion.

E. The first is a circumstance for which the astronomer seeks to provide an explanation; the second acknowledges a consideration that weighs against the explanation provided by the astronomer.

解析： 此题考查黑体句的作用。如前所述，逻辑文章中句子的作用分为：背景、前提、结论、中间性结论、与结论方向相反的前提和与结论方向相反的结论。因此，梳理清楚六个逻辑元素之间的区别后，做此类考题对学生而言不在话下。

句子作用题的基本解题步骤为：（1）判断两个黑体句之间的逻辑关系是顺承还是转折。（2）判断黑体句所起作用是六大逻辑元素中的哪一类。

将上述步骤应用于此题：

解题步骤1：两个黑体句分别描述了两个现象，合在一起推出结论，因此两句话之间不存在转折关系。

解题步骤2：通过意思来判断，得出文中最后一句话的主句（it is likely that some... being burned up）是结论（conclusion），第一个黑体句描述了一个现象（现象本身可以是背景或前提），第二个黑体句开头的Since提示该句是前提。

A项：后半句weight against 提示“转折逻辑”，据此可排除本项。

B项：后半句意思为第二个黑体句支持第一个黑体句。即使没有学习过逻辑六大元素，也知道从句的作用是服务于主句的，所以此项肯定不正确。

C项：没有发现错误点，两个现象被认为是用于支持结论的因素，至少不能说错，留着此项待比较。

D项：认为第一句话是支持结论的论据（属于前提），据此排除此项。

E项：后半句weight against 表明此项可排除。

此题答案为C项。

8.其他类

Yeasts capable of leavening bread are widespread, and in the many centuries during which the ancient Egyptians made only unleavened bread, such yeasts must frequently have been mixed into bread doughs accidentally. The Egyptians, however, did not discover leavened bread until about 3000 B.C. That discovery roughly coincided with the introduction of a wheat variety that was preferable to previous varieties because its edible kernel could be removed from the husk without first toasting the grain.

Which of the following, if true, provide the strongest evidence that the two developments were causally related?

A. Even after the ancient Egyptians discovered leavened bread and the techniques for reliably producing it were well known, unleavened bread continued to be widely consumed.

B. Only when the Egyptians stopped the practice of toasting grain were their stone-lined grain-toasting pits available for baking bread.

C. Heating a wheat kernel destroys its gluten, a protein that must be present in order for yeast to leaven bread dough.

D. The new variety of wheat, which had a more delicate flavor because it was not toasted, was reserved for the consumption of high officials when it first began to be grown.

E. Because the husk of the new variety of wheat was more easily removed, flour made from it required less effort to produce

解析： 此题让考生找一个选项，这个选项可以支持文中两个事件的因果联系逻辑。我们必须先找到具体事件。

原文前两句话（Yeasts capable of leavening bread ....Egyptians, however, did not discover leavened bread until about 3000 B.C）描述“发酵面包”的事件；之后的句子描述大麦（wheat）。所以，我们需要找“描述‘发酵面包与大麦’之间的关系的选项”。

A项提到发酵面包。

B项说了烤面包相关。

C项提到大麦之后又提到发酵面包。

D项提到大麦被消耗。

E项讲了大麦的壳。

只有C项两个事件都提到，最符合题目所问，因此得出答案为C项。

本章核心测试题

1. 逻辑六大元素是哪些？

2. 何为推理链（argument）？

如答案不能脱口而出，请回读本章。 j4zTR4Rlc/V7PYnmm4NJPaiC4iTjXFxdJ8Fu2PKrU6oTdYEM8Tj24yJKpTVULCBb