．—What’s 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
网友回答
(答案→)A. must
B. may
C. can
D. shall
解析：考查情态动词must的用法，这里表示“偏要”，句意：--那边低着头的男子怎么了？--如果你偏要知道的话，他被抓住偷我的自行车。选A。