rack one's brains 绞尽脑汁

“绞尽脑汁”，意思是苦思积虑，费尽脑筋，想尽办法；形容费尽心思去思考一件事情。与英文俗语“rack one's brains或cudgel one's brains”意思相近，表示“strain to remember or find a solution”。

例句：

他整个周末绞尽脑汁想办法解决这个问题。

He racked his brains all weekend trying to think of a solution to the problem.

我绞尽脑汁想回忆起我们把钥匙放在哪儿了。

I've been racking my brains trying to recall where we put the key.