问题
选择题
My cell-phone has disappeared. Who have taken it away?
A.could
B.should
C.must
D.might
答案
答案:A
考查情态动词。句意:我的cellphone不见了,会是谁把它拿走了呢?此处could have done表示“可能做过某事”。should have done表示“本来应该做某事(但实际上并没有做)”;must have done表示“一定做了某事”;might have done表示“也许做了某事”。