池州黄埔驾校大润发:______，many problems of space flight couldn’t have been solved

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If electronic computers were not invented
B. If electronic computers are not invented
C. Had electronic computers not been invented
D. Had electronic computers been invented

C. Had electronic computers not been invented
这是考察虚拟语气的一道题目,从couldn’t have been solved可知事情已经发生了,也就是说,如果前面的事情发生了,后面的事情就couldn’t have been solved了,had…not been是if electroic computers hadn't been invented的另一种形式，表示对过去的虚拟。此外，类似的还有把从句中的动词 were或 should 移到主语前面。

Were she younger, she would do it .

如果她年青点， 她就会干的。

Had he known her address, he would had gone to visite her.

如果他知道她的地址，他会去看她的。
这样可以了吗？如果想对虚拟语气有更多的了解，到这里看看：http://www.cycnet.com/englishcorner/grammar/mood.htm

C
句意上排除D
AB时态不对,应用过去完成时,因为主句用的是couldn't have been
D时态对,实际上是If electronic computers had been invented.的变形.虚拟语气中,把if去掉,用倒装,had提前.

If electronic computers were not invented

______，many problems of space flight couldn’t have been solved ______，many problems of space flight couldn’t have been solved ______，many problems of space flight couldn’t have been solved 怎样翻译 many problems are routine or anticipated they can help peopleto w_____out many problems they can't do easily. English problems english problems ENGLISH PROBLEMS English Problems some problems