题目

Jack _______ yet last night, otherwise he _______ me. 　 A. mustn’t have arrived; must have phoned 　  B. can’t have arrived; would have phoned 答案： B 解析: 否定推测要用can’t/couldn’t+…;与过去事实相反的虚拟语气,条件句用过去完成时态,主句用过去将来完成时态,即would/should/could/might+have+p.p.。

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