— Whats the matter with the man hanging his head there?— Well if you know he was caug

问题补充：

— Whats the matter with the man hanging his head there?

— Well, if you know, he was caught stealing my bike.

A. must

B. may

C. can

D. shall

答案：

(答案→)A. must

B. may

C. can

D. shall

解析：情态动词must在此表示“偏要，硬要”。句意：在那边垂着头的人怎么了？——如果你偏要知道的话（那我就告诉你），他在偷我自行车的时候被捉住了。