___a lady of her necklace,.the young man was arrested on the spot by a policeman .
问题描述：
___a lady of her necklace,.the young man was arrested on the spot by a policeman .
A having been caught robbing B caught robbing
Ccaught and robbing D being caught robbing
the answer is b,.TELL me why ,thanks ,catch doing
答
catch sb doing sth 抓到某人做什么（一般为不光彩的事）
由于catch 和逻辑主语 the young man 之间为被动关系,所以用过去分词短语作状语