Question

The explosion in the chemical plant ______ avoided had the county authorities, aiming too much at short-term interests, performed their duties from the beginning.

A. should be B. might be C. must have been D. could have been

Answer

D

【解析】

考查虚拟语气。句意：如果县政府从一开始就履行自己的职责，那么这座化工厂的爆炸本来是可以避免的。分析句子可知，本句是对过去时间的虚拟，if引导的条件句用过去完成时，if省略，句子倒装，所以主句是had the county authorities, aiming too much at short-term interests, performed their duties from the beginning，从句是 could have been。故D选项正确。

条件从句的谓语动词形式

主句谓语动词形式

与过去事实相反的假设

had done

would/could/might/should have done

与现在事实相反的假设

过去时(was→were)

would/could/might/should do

与将来事实相反的假设

过去时 (was→were ) ;

should do;

were to do

would/could/might/should do