987大全-131

mayce

1.        As measured by the Commerce Department, corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher costs.

(A) and have slipped since then, as many companies have been unable to pass on higher costs

(B) and have slipped since then, the reason being because many companies have been unable to pass on higher costs

(C) and slipped since then, many companies being unable to pass on higher costs

(D) but, many companies unable to pass on higher costs, they have slipped since then（A）

(E) yet are slipping since then, because many companies were unable to pass on higher costs

我想问E为什么不对，是说yet because 都不能乱加么？

那么A中的have been 能解释一下为什么用完成时态么？

谢谢！

(A) and have slipped since then, as many companies have been unable to pass on higher costs

(B) and have slipped since then, the reason being because many companies have been unable to pass on higher costs

(C) and slipped since then, many companies being unable to pass on higher costs

(D) but, many companies unable to pass on higher costs, they have slipped since then（A）

(E) yet are slipping since then, because many companies were unable to pass on higher costs

我想问E为什么不对，是说yet because 都不能乱加么？

那么A中的have been 能解释一下为什么用完成时态么？

谢谢！

carolhide

MM，语法区有下载大全注释，对每题大全都有前人的精彩解释，MM可以先去下这个，如果还有问题再发贴询问，谢谢MM配合啦。MM可先阅读一下发贴规则。

    

【发帖必读】─ ─ GMAT语法区版规
    

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frostone

Everytime when you see "since", it's a good indication of using perfect tense.  E should be eliminated because the tense does't match "..are slipping.., because ....were unbale...".  I would pick A for the right answer because it honors "since" by equipped the main sentence and its clause with perfect tense.