It ________be the vocabulary that caused you the problem in the exercise because you know a lot of words.                                                  (2013·安徽，34)

A．may	B．couldn’t
C．should	D．needn’t

—Why are your eyes so red？You________have slept well last night.
—Yeah，I stayed up late writing a report.                          (2013·四川，5)

A．can’t	B．mustn’t
C．needn’t	D．won’t

Since nobody gave him any help，he ________ have done the research on his own.
(2013·大纲全国，26)

A．can	B．must
C．would	D．need

—You needn’t take an umbrella.It isn’t going to rain.
—Well，I don’t know.It________do.                             (2013·北京，35)

A．might	B．need
C．would	D．should

Harry is feeling uncomfortable.He________too much at the party last night.(2013·辽宁，31)

A．could drink	B．should drink
C．would have drunk	D．must have drunk

No one________ be more generous；he has a heart of gold.         (2013·天津，9)

A．could	B．must
C．dare	D．need

He________sleep，although he tried to，when he got on such a hunt for an idea until he had caught it.                                                     (2013·湖南，32)

A．wouldn’t	B．shouldn’t
C．couldn’t	D．mustn’t

When I was a child，I ________ watch TV whenever I wanted to.        (2013·江西，29)

A．should	B．could
C．must	D．need

I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.                                                    (2012·新课标全国，30)

A．couldn’t	B．mustn’t
C．shouldn’t	D．needn’t

—God！My cell phone is missing.
—You ________ have left it at home.I heard you telephone our daughter in the bathroom.

A．shall	B．must
C．would	D．could