单选题 You ______ her in her office last Friday；she's been out of town for two weeks．
   A) needn't have seen    B) must have seen    C) might have seen    D) can't have seen
【正确答案】 D
【答案解析】上星期五你不可能在办公室里见过她，她去外地已经有两个星期了。
   这道题考查的是情态动词完成时表示推测，can't have done是对过去事实的否定推测。