1.真没见过There must be some water in your head.说人脑子有病常用的是：You must be out of your mind.我见过的比较好玩的是：Your sense must be knocked out of your mind.
2.I think本身就已经所很常用,比较口语了,在随便的要看语境了,比如,直接说to me对我而言,as far as I know或to the best of my knowledge就我所知,之类的,很多,但具体用起来要有少许的区别
3.挑衅经常看到的只是provoke,挑衅的provocative,如果是富有攻击性的,口语里常用aggressive
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