bad-mouth 严厉批评，说坏话，恶意攻击

　　Why do you always bad-mouth my friends?

　　你为什么总说我朋友的坏话？

　　I don't think it's right to bad-mouth others. So don't do it.

　　我认为说别人坏话是不对的，你最好别这样做。

　　疯狂练习吧！