A police spy or informer.

警方的线人或告密者。

An unpleasant, annoying person who makes things difficult for others.

令人讨厌、给他人添乱的人。

To act as a spy or informer; to tattle.

充当线人或告密；打小报告。

To annoy or irritate.

使人恼火或烦躁。

To complain.

抱怨。

To stop.

停止。