A: Tim, knock it off, would you? Your singing is killing me.Tim,别唱了好吗?你的歌声简直要我的命!
B: Hey! You're rude.嘿,你怎么那么没礼貌啊!
"Knock it off!" 是叫 (某人) 停止做某事的意思,与 "Cut it out!" 和 "Stop it!" 都是同样的意思。