—Does your uncle still smoke?—He given it up. It’s two years ever since he .A. can’t have;

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A. can’t have; smoked
(答案→)B. may have; smoked
C. should have; has smoked
D. should have; didn’t smoke
解析：本题考查情态动词和时态。may have done 表示“可能已经做某事了”；第二空表示“他不吸烟有两年了”，since表时间时，所接从句谓语动词要用过去时或过去完成时。此句型中用延续性动词表示动作停止。