She looks very happy. She_________ the exam.
A.can have passed B.should have passed C.must have passed D.could have passed
Tom is nice and lovely, but he be very naughty at times.
A.can B.shall C.must D.should
—You rang me up at about 10:00 last night, didn't you?
—No, I didn't phone you. It someone else.
A.must have been B.could be C.must be D.could have been
While it wasn’t the goal of the trip, I was rewarded with fresh insights, ones that ________ to me during the regular course of business.
A.might never happen B.could never have happened
C.should not happen D.needn’t have happened
If customers think the services are worthwhile, I do believe many of them ________ accept and pay for them.
A.had better B.may well C.may as well D.may
From her knowledge of Douglas's habits，she feels sure that the attacker last night ___________Douglas.
A. mustn't have been B. can't have been
C. shouldn't have been D. wouldn't have been
