求NN们解答大全557的一个问题~

新新新新新人

557, sec01-06

One of every two new businesses fail within twoyears.

(A) fail

(B) fails

(C) should fail

(D) may have failed（B）

(E) has failed

Choice A is wrong because the verbfail does not agree in number with One, the subject of thesentence; businesses is not the subject of the sentence but the objectof a prepositional phrase. Choice B is correct. In choice C, should failis inappropriate for astatement of fact and carries the unintended suggestion of ought tofail. In choices D and E, may have failed and has failedwrongly refer to a completed action rather than an ongoing condition. This question is of middlediffculty.

想请问为何不能选E？

看了大全的解释和之前的讨论帖，还是不明白

为什么原文一定是一般规律而非是从过去两年发生总结出来的呢

困惑困惑

alzn2765

没有语境，这就是一个一般律规，用一般现在时。完成时必须有完成时态提示词since等，或者有明显的语境才能用。不然，这题用一般过去将来完成进行时为啥不可以？
选B不选E不代表E就错误了，只是这道题B比E要好。

新新新新新人

alzn2765 发表于 2016-2-18 20:36
没有语境，这就是一个一般律规，用一般现在时。完成时必须有完成时态提示词since等，或者有明显的语境才能 ...

谢谢alzn！