英语 (17 12:23:16)

我觉得AD都可以,这个题出的有矛盾若选A是用may对事物的推测若选D是虚拟语气,对过去的推测,would have done sth表示我本该发生什么而没发生在条件虚拟从句中,主句用would（should,could,might）have done表示与过去事实相反情态动词 + have done sth这个结构有着特殊意义：用来表示猜测(设想可能发生过什么事情)或想象(设想可能出现过什么不同的情况)①should (ought to) have done sth 本来该做而未做This wall oughtn’t to have been painted blue。②need have done sth 本来有必要做而未做You needn’t have told her the news。③must have done sth 对过去所做动作的肯定推测---We went to Paris。---That must have been nice。④can have done sth 对过去所做动作的否定或疑问推测I don’t think he can have heard you。Call again。Where can John have put the matches?⑤may (might) have done sth 过去可能发生某事,与could相比,may和might可能性较小,might 可能性更小;might 也可表示过去可能发生而未发生的事情。Polly’s very late----she may (might) have missed heretrain。You were stupid to try climbing there。You might have killedyouself⑥could have done sth●推测过去”可能“发生某事 (同can,但can不用肯定句)She could have gone off with some friends。●表示过去没有实现的可能性：某事可能发生,但却没有发生You were stupid to go skiing there----you could have brokenyour leg。●表示有能力做而未做(虚拟语气)You could have helped me !(You were able to help me,but you didn’t。)