Question

I have lost one of my gloves. I _____ it somewhere.

A．must drop	B．must have dropped
C．must be dropping	D．must have been dropped

Answer 1

B

由题干而知不用被动，排除选项D；题干说“已经丢了”，排除选项C；选项A“情态动词+动词原形”，表示对现在或将来的事情推测；选项B“情态动词+动词的完成时”表示的是对过去或已经发生的事情的推测判断，所以选B。