Question

--- Have you told him we have changed the plan?
I _____ have, but I haven’t done it yet.

A．must

B．ought to

C．needn’t

D．can’t

Answer 1

B

試題分析：考察情態(tài)動(dòng)詞用法。A必須，一定；B應(yīng)該；C不必；D不可能；ought to have done本應(yīng)該做某事，實(shí)際上卻做未。Must have done一定做了某事；needn’t have done本不需要做某事，實(shí)際上卻做了。句意：—你告訴他我們改變計(jì)劃了嗎？—我本應(yīng)該告訴他，但是我還沒(méi)有告訴他呢。根據(jù)句意說(shuō)明B正確。
點(diǎn)評(píng)：本題是高考必考考點(diǎn)，一定要牢記句型意思。must have done過(guò)去肯定做了某事。should have done 本應(yīng)該做而實(shí)際未做。can’t have done 過(guò)去不可能做了某事；shouldn’t have done 本不應(yīng)該做而實(shí)際做了。 need have done 本有必要做某事；needn’t have done 本沒(méi)有必要做某事；注意沒(méi)有 mustn’t have done的形式。