Question

—Does your uncle still smoke?
—He       given it up. It’s two years ever since he      .

A．can’t have; smoked	B．may have; smoked
C．should have; has smoked	D．should have; didn’t smoke

Answer 1

B

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。