语法解析：情态动词时态

 情态动词

1.You ______ Jim anything about it. It was none of his business. (2004)
A. needn’t have told B. needn’t tell C. mustn’t have told D. mustn’t tell
(A，needn’t have done表示本不必做而做了。没有mustn’t have done的形式，但可以说can’t have done，表示不大可能。)
2.He ______ the 8:20 bus because he didn’t leave home till 8:25. (1994)
A. couldn’t have caught B. ought to have caught
C. shouldn’t have caught D. must not have caught
(A，couldn’t have done表示不可能做了某事。)
3.He _____ unwisely, but he was at least trying to do something helpful. (1999)
A. may have acted B. must have acted C. should act D. would act
(A，may have done表示过去可能做过某事，B表示一定做过，推测的可能性很大。)
时态
1.How can I ever concentrate if you _____ continually ____ me with silly questions? (97)
A. have … interrupted B. had … interrupted
C. are … interrupting D. were … interrupting
(C，现在进行时与always, continually, constantly连用表示某种带有感**彩，经常发生的动作。本句暗含责备之义。)
2.Come and see me whenever ______. (97)
A. you are convenient B. you will be convenient
C. it is convenient to you D. it will be convenient to you
(C，whenvever引导的时间状语从句用一般现在时表将来;convenient一词只能说it is convenient to sb.)
3. For some time now, world leaders __ out the necessity for agreement on arms reduction. (02)
A. had been pointing B. have been pointing C. were pointing D. pointed 1
(B，现在完成进行时表示动作从过去某一时间开始延续到现在，并可能继续。)
4.Jack 2 _____from home for two days now, and I am beginning to worry about his safety. (03)
A. has been missing B. has been missed C. had been missing D. was missed
(A，同上。“杰克离家两天(到现在还没回)，我开始担心他的安全。”)
5. _________ conscious of my moral obligations as a citizen. (05)
A. I was and always will be B. I have to be and always will be
C. I had been and always will be D. I have been and always will be
(D， ABC三项前后两个时态不一致，只有D项中现在完成时与将来时搭配一致。)时态
1.How can I ever concentrate if you _____ continually ____ me with silly questions? (97)
A. have … interrupted B. had … interrupted
C. are … interrupting D. were … interrupting
(C，现在进行时与always, continually, constantly连用表示某种带有感**彩，经常发生的动作。本句暗含责备之义。)
2.Come and see me whenever ______. (97)
A. you are convenient B. you will be convenient
C. it is convenient to you D. it will be convenient to you
(C，whenvever引导的时间状语从句用一般现在时表将来;convenient一词只能说it is convenient to sb.)
3. For some time now, world leaders __ out the necessity for agreement on arms reduction. (02)
A. had been pointing B. have been pointing C. were pointing D. pointed
(B，现在完成进行时表示动作从过去某一时间开始延续到现在，并可能继续。)
4.Jack _____from home for two days now, and I am beginning to worry about his safety. (03)
A. has been missing B. has been missed C. had been missing D. was missed
(A，同上。“杰克离家两天(到现在还没回)，我开始担心他的安全。”)
5. _________ conscious of my moral obligations as a citizen. (05)
A. I was and always will be B. I have to be and always will be
C. I had been and always will be D. I have been and always will be
(D， ABC三项前后两个时态不一致，只有D项中现在完成时与将来时搭配一致。)