The air will be further polluted unless some measures________.
A. will be taken
B. are taken
C. were taken
D. had been taken
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When David arrived, he learned Jack ______for almost two hours.
A. had gone
B. had set off
C. had left
D. had been away
You should have put the yogurt into the fridge. I expect it _____undrinkableby now.
A. became
B. had become
C. has become
Even if she herself_______ tomorow, it _____too late to do anything.
A. will come; is
B. should come; were
C. comes; will be
A bell rang again! It was the third time someone ______me that evening.
A. has interrupted
B. had interrupted
C. to have interrupted