【题目】-Where is my suitcase？
-Somebody_______it away by mistake．
A. must have takenB. could take
C. should takeD. must take
在线课程【答案】A
【解析】
考查情态动词+have done。句意：我的手提箱在哪里？一定是有人误把它拿走了。must have done一定做某事．表示对过去事情的较有把握的推测，这时只能用在肯定句中，意思是"肯定/必须已经干过…"．could do 能够做某事，should do 应该做某事，must do必须做某事。故A选项正确．