GMAT考试-Testprep数学精解（4）

　　argument. Finding the suppressed premise， or assumption， of an argument can

　　be difficult. However， on the GMAT you have an advantage——the suppressed pre

　　mise is listed as one of the five answer-choices. To test whether an answer-

　　choice is a suppressed premise， ask yourself whether it would make the argum

　　ent more plausible³. If so， then it is very likely a suppressed premise.

　　Example：

　　American attitudes tend to be rather insular⁴， but there is much we can learn

　　from other countries. In Japan， for example， workers set aside some time ea

　　ch day to exercise， and many corporations provide elaborate exercise facilit

　　ies for their employees. Few American corporations have such exercise progra

　　ms. Studies have shown that the Japanese worker is more productive than the

　　American worker. Thus it must be concluded that the productivity of American

　　workers will lag behind their Japanese counterparts， until mandatory⁵ exerci

　　se programs are introduced.

　　The conclusion of the argument is valid⁶ if which one of the following is ass²

　　umed？

　　（A） Even if exercise programs do not increase productivity， they will improv

　　e the American worker's health.

　　（B） The productivity of all workers can be increased by exercise.

　　（C） Exercise is an essential factor in the Japanese worker's superior produc

　　tivity.

　　（D） American workers can adapt to the longer Japanese work week.

　　（E） American corporations don't have the funds to build elaborate exercise f

　　acilities.

　　The unstated essence of the argument is that exercise is an integral part of

　　productivity and that Japanese workers are more productive than American wo

　　rkers because they exercise more. The answer is （C）。

　　Counter-Premises

　　When presenting a position， you obviously don't want to argue against yourse

　　lf. However， it is often effective to concede certain minor⁷ points that weak

　　en your argument. This shows that you are open-minded and that your ideas ar

　　e well considered. It also disarms⁸ potential arguments against your position

　　…… For instance， in arguing for a strong， aggressive police department， you m

　　ay concede that in the past the police have at times acted too aggressively.

　　Of course， you will then need to state more convincing reasons to support y

　　our position

Example：

　　I submit that the strikers should accept the management's offer. Admittedly，

　　it is less than what was demanded. But it does resolve the main grievance——

　　inadequate⁹ health care. Furthermore， an independent study shows that a wage

　　increase greater than 5% would leave the company unable to compete against J

　　apan and Germany， forcing itsintosbankruptcy.

　　The conclusion， “the strikers should accept the management's offer，” is stat

　　ed in the first sentence. Then “Admittedly” introduces a concession¹⁰； namely，

　　that the offer was less than what was demanded. This weakens the speaker's

　　case， but it addresses a potential criticism of his position before it can b

　　e made. The last two sentences of the argument present more compelling reaso

　　ns to accept the offer and form the gist¹¹ of the argument.

　　Following are some of the most common counter-premise indicators¹²：

　　Counter-Premise Indicators

　　but despite

　　admittedly except

　　even though nonetheless

　　nevertheless although

　　however in spite of the fact

　　As you may have anticipated， the GMAT writers sometimes use counter-premises

　　to bait wrong answer-choices. Answer-choices that refer to counter-premises

　　are very tempting¹³ because they refer directly to the passage and they are i

　　n part true. But you must ask yourself “Is this the main point that the auth

　　or is trying to make？“ It may merely be a minor concession.

　　Logic¹⁴ II （Diagramming）

　　Most arguments are based on some variation of an if-then statement. However，

　　the if-then statement is often embedded¹⁵ in other equivalent structures. Dia

　　gramming brings out the superstructure and the underlying¹⁶ simplicity¹⁷ of argu

　　ments.

　　If-Then

　　A——>B

　　By now you should be well aware that if the premise of an if-then statement

　　is true then the conclusion must be true as well. This is the defining chara

　　cteristic of a conditional statement； it can be illustrated as follows