catch sb．doing sth；? be (get) caught in sth．
catch sb．doing sth．作“碰（遇）上某人正在做某事”解。例如：
The policeman caught two men fighting in the street．警察碰见两个人在街上打架。
The man was caught stealing the apples．那人偷苹果时，被当场发现。
be (get) caught in sth．“遇上……而受阻”之意。例如：
I got caught in the traffic．我因交通堵塞而受阻。
I was caught in a storm on my way to school．我在去学校的路上遇到了暴雨。
