GRE阅读逻辑题讲解

1、逻辑题讲解版 1.0版写在前面:1. 请同学们先在讲义上做题,带着问题来看这个讲解版。此为 1.0版。适当时候我会加入新的题目的 讲解,将其升级为 2.0 或者 3.0版本。不过这个目前应该是够用了。2. 以下的正确答案用黄色标示,错误选项的错误理由用 “ 标示。3. 逻辑题中的错误选项大多都是跟本题没有任何关系的。逻辑题的错误选项的编撰者遇到的最大的 问题就是由于逻辑题的文章篇幅较短,无法使用文章中已有的部分来编制错误选项。于是,只能从 文章之外寻找一些线索了。4. 此处的 17题虽然不多,但是有一定的代表性。请各位在课外多做一些其它的 GMAT 的逻辑题强化此 方面的能力和意识。5. 当然

2、,各位应该知道 GRE 的 Verbal 部分的逻辑题数量较少。主要还是纯阅读部分的掌握,还记得我 们上课经常说的那些东西吗? 我想我上课中经常重复的东西可能还在你们耳边 “ 阴魂不散 ” 吧? “ 三强 词汇 ” , “ 四大金刚 ” , “ 取非 ” “ 同义变换 ” 。归纳题:例子 1:T o be mentally healthy, people must have self-respect. People can maintain self-respect only bycontinually earning the respect of others they esteem. Th

3、ey can earn this respect only by treatingthese others morally.Which of the following conclusions can be properly drawn from the statements above?解释:此题采用公共元素直推法。 读完题目后我们知道正确答案肯定要跟 mentally healthy 和 treating these others morally 有关。(A People who are mentally healthy will be treated morally by others.

4、(B People who are mentally healthy will have treated morally those they esteem.(C People who are mentally healthy must have self-respect in other to be treated morally by others.(D People can expect to be treated morally by others only if they esteem these others.(E People who have self-respect seld

5、om treat morally those esteem.其它的选项都跟这个没有关系例子 2:Experienced pilots often have more trouble than novice pilots in learning to fly the newly developed ultralight airplanes. Being accustomed to heavier aircraft, experienced pilots, when flying ultralight craft, seem not to respect the wind as much as t

6、hey should.The passage implies that the heavier aircraft mentioned above are解释:此题采用无关词排除法。 读完题目后我们知道正确答案肯定要跟飞机的轻 重和风有关。(A harder to land than ultralight aircraft(B not as popular with pilots as ultralight aircraft(C not as safe as ultralight aircraft(D more fuel-efficient than ultralight aircraft(E

7、easier to handle in wind than ultralight aircraft其它的选项都跟这个没有关系,于是不予选择例子 3:While this program enabled many minority entrepreneurs to form new businesses, the results were disappointing, since managerial inexperience, unfavorable locations, and capital shortages led to high failure rates. Even years a

8、fter the SBA program was implemented, minority business receipts were not quite two percent of the national economys total receipts.Which of the following does the author cite to support the conclusion that the results of the SBA program were disappointing?解释:此题读完后应该知道作者认为 SBA 项目失败的原因是少数民族企业的收入占 到国民

9、经济的比例太低,即这是一个相对量,而非绝对量。因此 A , B , E 选项都是 number 这个绝对量。因此 C 中的 small percentage 符合题目要求,而 D 中的 “ repay federally guaranteed loans” 与本题无关(A The small number of new minority enterprises formed as a result of the program(B The small number of minority enterprises that took advantage of the management and

10、 technical assistance offered under the program(C The small percentage of the nations business receipts earned by minority enterprises following the programs, implementation(D The small percentage of recipient minority enterprises that were able to repay federally guaranteed loans made under the pro

11、gram(E The small number of minority enterprises that chose to participate in the program演绎题假设题例子 4:New Jersey has one of the lowest motor vehicle fatality rates in the country, and it is one of the few states that require extensive annual automobile safety inspections. , all states should adopt simi

12、lar safety inspection procedures.The argument above is based on which of the following assumptions?解释:此题中 Therefore 表明了逻辑关系中的前因后果。此题的推理过程为:新泽西 的机动车死亡率低,而同时新泽西大范围地执行了年度的机动车安全检查。因此,作 者因此就把该州的机动车死亡率低归因于该州实行了机动车的安全检查。所以,正确 选项应该与此推理有关。(C Annual automobile safety inspections contribute significantly to ho

13、lding down New Jerseys fatality rate.(E 例子 5:The federal government expects hospitals to perform 10,000 organ transplants next year. But it is doubtful that this many donor organs will be available, since the number of fatalities resulting from car and motorcycle accidents has been dropping steadily

14、 over the past decade.The argument above makes which of the following assumptions?解释:此题中 Since 和 resulting from 表明了因果关系。因此此题的推理过程为:因为 死于机动车事故的人数下降,因此担心没有 10000个器官可供使用。所以,正确选项 应该与以上的关键词(器官,机动车事故,死亡有关。因此只能选择 A 。(A A significant number of the organs used in transplants come from people who die in car a

15、nd motorcycle accidents.(B The number of car and motorcycle accidents will increase significantly during the next year.(C No more than 10,000 people will be in need of organ transplants during the next year.(D In the past the federal governments estimates of the number of organ transplants needed du

16、ring a given year have been very unreliable.(E For any given fatality resulting from a car or motorcycle accident, there is a hospital in the vicinity in need of an organ for a transplant.加强题例子 6:Because incumbent members of Congress are given a great deal of attention by the news media and because

17、they enjoy such perquisites as free mail privileges and generous travel allowances, incumbents enjoy an overwhelming advantage over their challengers in elections for the United States Congress.Which of the following,if true,best supports the claim above?解释:此题中 Because 表明了因果关系。此题的推理过程为:因为在朝官员得到了 更多的

18、媒体的关注以及享受了各种补贴,因此在朝官员比在野官员更容易赢得国会选 举的胜利。所以,如要支持该推理必须要选择一个与此相关的选项。(B In the last congressional elections, 98 percent of the incumbents in the House of Representatives who were seeking reelection won.(C Incumbent members of Congress are news media.(D The support that political station action committee

19、s provide to challengers for congressional seats often (相当于抵消的意思 the perquisites enjoyed by incumbent members of Congress.此选项的问题在于 削弱了在朝的优势。但是必须要选择一个使在朝官员有优势的选项。因此,此选项有削弱题的意味did not pose a serious threat to their chances for reelection.用文章中没有提到的内容,直接加强文章结论例子 7:Recent surveys show that many people wh

20、o seek media help are under a great deal of stress. Medical research also shows that stress can adversely affect an individuals immune system, which is responsible for combating many infections. Thus when a person is under stress, he or she is more likely to become ill.Which of the following,if true

21、,would most strength the conclusion above?解释:此题中 Thus 表明了因果关系。此题的推理过程为:寻求医疗帮助的人处在巨 大的压力之下以及研究表明压力会影响人的免疫系统。所以,如要支持该推理,必须 要选择一个与压力和寻求医疗帮助有关的选项。(B Many businesses during periods when employees feel pressured by management.(C There is a marked decrease in the number of complaints (生病 presented at colle

22、ge infirmaries during vacation time. 此选项说明的是 “ 压力小,得病的就少 ”(D There is a marked increase in the number of illness treated at college infirmaries around the time of examinations.此 选项说的是 “ 压力大,就会得病 ”相比较而言,还是 D 支持的力度最大了例子 8:A test of the National Weather Services storm detecting radar systems found that

23、 the 1957 system isten times more reliable than the new computerized system. Therefore the technology used in the new radar system mustbe less sophisticated than the radar technology used in the 1957 system.The conclusion drawn above depends on which of the following questionable assumptions?解释:此题中

24、Therefore 表明了因果关系。此题的推理过程为:因为 1957年的系统比 新的计算机化了系统精确 10倍。所以,新的系统的技术没有 1957年系统的系统复杂。 本题假定 系统技术的复杂程度决定着系统的可靠性。(A(B The level of sophistication of the technology used in storm-detecting radar system can be determined from the reliability of the system.(Cservices.其它几个选项都出现了与本题不相关的内容。削弱题例子 9:Scientists no

25、w believe that artificial-hip implants, previously thought to be safe, may actually increase the risk of cancer in recipients after about 45 years of use. Though these implants do improve the quality of recipients lives, the increased risk of cancer is an unacceptable price to pay for these improvem

26、ents. Therefore , they should be banned.Which of the following,if true,is the strongest counterargument to the argument above?解释:此题中 Therefore 表明了因果关系。此题原因为:人造臀部虽然能够提高受体 的生活质量,但是会在 45年后增加引发癌症的机率。所以,这种技术应该被禁止。想 削弱这个命题就是要为这个技术 “ 辩护 ” 。选一个为其辩护或者高唱赞歌的选项吧!and these complications can themselves be crippli

27、ng or even fatal.未唱赞歌。(B Almost all artificial-hip implant recipients receive their implants at an age when they are unlikely to live more than an additional 30 years. 这样,受体在未到 45年的时候就已经翘辫子了,因此此选项在为此种技术 “ 辩护 ”(C Although artificial-hip implants increase the risk of cancer after about 45 year of use,

28、 a few of the cancers they induceare not fatal. 依然承认了得癌症的可能性, “ 辩护 ” 力度不及 B 。(D Since artificial-hip implants are not very common, banning them would cause little hardship. 相对比较中性。(E Although the benefits of artificial-hip implant surgery have remained substantially the same overthe past decade, the

29、 price of the surgery has risen considerably. 此选项强调是此技术的缺点:价格太高此题的启示在于:从这四个错误的选项可以看出错误选项的类型:1. 相反的选项,如削弱题中的支持类的选项。如此题中的 A 和 E2. 无关选项,如 D3. 与正确选项形成 PK 关系,但是相比之下没有正确选项符合要求。例子 10:Metropolis regulation limiting to four days the period during which milk can be sold to consumers after pasteurization is un

30、reasonable. Under optimal conditions, pasteurized milk kept at 40 degrees Fahrenheit remains unspoiled for at least 14 days. If Metropolis current limitation were changed to eight days, milk prices would drop, but product quality would be unaffected.Which of the following,if true,would most seriousl

31、y weaken the conclusion drawn above?解释:此题中虽然没有具体的信号词表明其逻辑关系。但是可以看出:因为在最 佳情况下,即在 40华氏度保存牛奶,牛奶 14天都不会变质。所以,作者认为可以如果 把牛奶的保质期调整为 8天,牛奶价格将会下降。想削弱此命题有以下几种思路:1、否定前提:牛奶不可能在最佳条件下保存。2、否定前提:即便在最佳条件下保存,牛奶 8 (<14天就变质了3、否定结论:将牛奶保质期调整为 8天,牛奶价格也不会下降以上任何一个思路都可以削弱该结论(A Most consumers keep milk no more than three d

32、ays after purchase.(B A recent survey showed that 20 percent of Metropolis consumers favored extending the currentlimitation on the sale of milk to 8 days.(C Metropolis grocery-store owners would prefer small, frequent deliveries of milk to larger, infrequent deliveries.(D Milk kept longer than 14 d

33、ays after pasteurization generally presents no medical dangers if consumed. 支持了该结论(E In Metropolis, conditions for handling and storing milk after pasteurization are seldom close to optimum.因此选择 E ,其它几个跟事先的思路不符例子 11:The country of Maravia has severe air pollution, 80 percent of which the exhaust fum

34、esof cars. In order to reduce the number of cars on the road, the government is raising taxes on the costof buying and running a car by 20 percent. This tax increase, therefore will significantly reduce air pollution in Maravia. Which of the following,if true,most seriously weakens the argument abov

35、e?解释:此题中 is caused by和 therefore 表明其逻辑关系:因为城市中 80%的污染是由过多的尾气排放导致的。政府正在提高买车和养车的费用 20%,希望借此降低汽车的数 量。所以,作者认为这样可以降低城市的污染。想削弱此命题有以下几种思路:1、该国的 80%污染并非来自于汽车尾气 ;2、提高买车和养车费用并不会减少车的数量,于是不能降低污染 ;任何一个选项应与上面的内容相关。(A(B(C(DNinety percent of the population of Maravia is very prosperous(富有 and has a substantial amou

36、nt of disposable income.(可支配收入 (EIn Maravia, cars that emit relatively low levels of pollutions cost 10 percent less to operate, on average, than do cars that emit high levels of pollutions.削弱了文章手段达到目的的可能性。II. 解题方法 2:它因法,即其它因素导致了结论而并非文中的那个原因例子 12:The excessive number of safety regulations that the f

37、ederal government has placed on industry poses more serious hardships for big businesses than for small ones. Since large companies do everything on a more massive scale, they must alter more complex operations and spend much more money to meet government requirements.Which of the following,if true,

38、would most weaken the argument above?解释:此题中 Since 表明其逻辑关系:因为大公司的规模效应所带来的更复杂的操 作和更多的开销。所以,作者认为关于安全的规定对大公司影响比小公司大。想削弱 此命题有以下几种思路:1、否定前提:大公司的规模效应不会带来更多复杂的操作以及更多的开销。2、否定结论:小公司比大公司更容易受到安全规定的影响,即选一个对小公司不 利的选项。任何一个选项应与上面的内容相关。(A Small companies are less likely than large companies to have the capital reser

39、ve for improvements.large companies.(C Safety regulation codes are uniform, established without reference to size of company. 但这并不等于对于大公司来说 不会带来更多的开销8. 解释题例子 13:The population of elephant seals, reduced by hunting to perhaps a few dozen animals early in this century, has soared under federal protect

40、ion during the last few decades. However, the species repopulated itself through extensive inbreeding, it now exhibits a genetic uniformity that is almost unparalleled in other species of mammals, and it is in far greater danger of becoming extinct than are most other species.Given the information i

41、n the passage above, which of the following is most likely the reason that other species of mammals are less likely than elephant seals to become extinct?解释:此题中 because 和 thus 表明其逻辑关系:因为象海豹近亲繁殖而导致的遗传单 一性。所以,作者认为象海豹相对于其它种群更容易有灭绝的危险。题目问的是其它 的哺乳类动物没有象海豹那样容易灭绝的原因。答案必须跟遗传有关。解释题的解答依靠常识(AOther species of m

42、ammals have large populations, so the loss of a few members of the species is not significant.(BOther species of mammals have increased their knowledge of dangers though the experience of generation after generation of animals.(CIn other species of mammals, hunters can readily distinguish between ma

43、les and females or between young animals and adults.(DIn other species of mammals, some members of the species are genetically better equipped to withstand a disease or event that destroys other members of the species.(EOther species of mammals have retained habits of caution and alertness because t

44、hey have not been protected as endangered species.I. 解释矛盾:例子 14:During the day in Lake Constance, the zooplankton D. hyalina departs for the depths where food is scarce and the water cold. D. galeata remains near the warm surface where food is abundant. Even though D. galeata grows and reproduces mu

45、ch faster, its population is often outnumbered by D. hyalina.Which of the following,if true,would help resolve the apparent paradox presented above?解释:此题中奇怪现象就是 h 白天沉入食物少,水温低的湖底,而 g 留在食物丰富 的湖面。但是 h 的数量多于 g 。任何一个选项应该能够解释 h 的数量比 g 多,或者 g 的数量比 h 少。AB Predators of zooplankton, such as whitefish and perc

46、h, live and feed near the surface of the lake during the day.E D. galeata produces twice as many offspring per individual in any given period of time as does D. hyalina. 该选项刚好相 反例子 15:For the United Stats meat industry, there is good news and bad news. The bad news in that over the last three years

47、people in the United States have been eating less meat. The good news is that during this same time period meat producers profits have risen steadily.Which of the following,if true during the last three years,contributes most to a resolution of the apparent discrepancy above?解释:此题中奇怪现象就是美国人肉消耗量下降,可是

48、美国的肉类生产商的利润 却稳步上升。解题思路如下,利润必然和需求和价格有关。1、肉类价格上升所带来的正面影响超过了由于消耗量下降所带来的负面影响2、美国的消耗量是少了,其它地方的需求量上升了。(A(BIn the United States many new restaurants that specialize in vegetarian meals have opened.以上两个选项解释了为什么美国人的肉类消耗量下降,但是没能解释为什么利润却上升了。(CCompetition from the growing fish industry has forced meat producers

49、 to sell meat at bargain prices in an attempt to attract more consumers. 与价格应该上升相反(DCountries that are unable to produce enough meat for their populations have become a new and lucrative market for United States meat producers.正好讲到需求量上升(EMeat producers have invested large amount of money on advertis

50、ing in order to win back consumers who have decreased their meat consumption. ” 在广告上化很多钱 “ 倒是说明了为什么肉类行业的利润下降(而不是上 升,因为增加了一块新的支出。9. 填空题例子 16:Observations of the Arctic reveal that the Arctic Ocean is covered by less ice each summer than the previous summer. Ifthis warming trend continues, within 50 y

51、ears the Arctic Ocean will be ice free during the summer months. This occurrence would in itself have little or no effect on global sea levels, since the melting of ice floating in water does not affect the water level. However, serious consequences to sea levels would eventually result, because _.Which of the following most logically completes the passage?解释:此题说道水中融化的冰本身对于海平面没有什么影响。但是从文章最后一 句应该可以知道肯定是其它因素导致了海平面的变化。A large masses of floating sea ice would continu