---Where is my pen?
--- I it.
A. might lose
B. wouldn’t have lost
C. should have lost
D. must have lost
网友回答
A. might lose
B. wouldn’t have lost
C. should have lost
(答案→)D. must have lost
解析：本题考查情态动词。从原题中Where is my pen?这一信息句可告诉考生，“笔丢了”，丢的动作是过去发生的。因此用must + have done表示对过去事实的肯定猜测。