He looked around and caught a man _____ his hand into the pocket of a passenger.
A. put B. to be put C. to put D. putting
He looked around and caught a man _____ his hand into the pocket of a passenger.
A. put B. to be put C. to put D. putting
D
catch sb doing sth表示发觉或当场捉住 sb在做一件事情。