2.It was indeed a clever plan to entrap his opponent， but in the end he was hoist by his own petard.
设圈套陷害他的对手固然是个妙计， 可是到头来却是害人反害己。
3.The criminal was hoist with his own petard when he tried to kill his wife, because he accidently drank the poison that he intended to give to her.
这个罪犯想谋杀他的妻子，但害人反害已；因为他不留神喝了他打算毒害他妻子的毒药。
4.The criminal was hoist with his own petard when he tried to kill his master,because he accidentally drank the poison that he intended to give to him.
那罪犯试图谋杀师傅时，反而害了自己，因为他意外地喝下了他欲给师傅的毒药。
