OG13 SC 第40题 HELP！！

ricci56

40. The Organization of Petroleum Exporting Countries (OPEC) had long been expected to announce a reduction in output to bolster sagging oil prices, but officials of the organization just recently announced that the group will pare daily production by 1.5 million barrels by the beginning of nextyear, but only if non-OPEC nations, including Norway, Mexico, and Russia, were to trim outputby a total of 500,000 barrels a day.

(A) year, but only if non-OPEC nations, including Norway, Mexico, and Russia, were to trim output

(B) year, but only if the output of non-OPEC nations, which includes Norway, Mexico, and Russia, is trimmed

(C) year only if the output of non-OPEC nations, including Norway, Mexico, and Russia, would be trimmed

(D) year only if non-OPEC nations, which includes Norway, Mexico, and Russia, were trimming output

(E) year only if non-OPEC nations, including Norway, Mexico, and Russia, trim output

C选项答案说 would in front of the passive verb be trimmed is redundant，为什么是多余的呢

ricci56

顶

ricci56

ricci56

召唤大神

HerringtonD

http://forum.chasedream.com/GMAT_SC/thread-66894-1-1.html

ricci56

http://forum.chasedream.com/GMAT_SC/thread-66894-1-1.html

-- by 会员 HerringtonD (2012/10/24 17:59:23)

谢谢！明白了

EMMALIULIU

If从句不能有would，should。

Hendy

If present, then present;
If present, then can or may
If present, then future;
If past , then would or could;
If past perfect, then would perfect or could perfect

The helping verbs would and should never go into  the if part of the sentence.

385643hyp

刚好做到这一题，讲一下我有些附会的解释：
A&B. but only if被排除是因为之前已经有一个but了，两个but的连续转折很容易产生句意混乱
C & D被排除，是因为only if的主句是讲OPEC自己pare daily production只要在non-OPEC也减产的情况下，而C, D用了被动语态与主句的主动pare daily production不相符。