---Whydon’tyouwearyourjoggingshorts,Mum? ---Well,myleg...

问题详情：

 ---Why don’t you wear your jogging shorts, Mum?

  ---Well, my legs are too skinny, if you ____ know.

  A. should     B. can         C. need       D. must

【回答】

D

知识点：情态动词

题型：选择题