What were you thinking? 你到底在想什么？
例句：
You skipped 5 classes in the past two were you thinking?
你在过去两天逃了五节课。你到底在想什么？
How can you just jump down?It's too were you thinking?
你怎么可以跳下去？太危险了。你到底在想什么？
I can't believe you stole the were you thinking?
我不敢相信你偷了钱。你到底在想什么啊？