We’re all scratching our heads for an answer to the problem.

为了找到这的答案绞尽脑汁。

I’ve been racking my brains all day trying to remember his name.

一整天绞尽脑汁，想要回忆起他的名字。

His classmates were labouring with elementary algebra.

他的同学正在绞尽脑汁地演算初等数。

He had to rack his brains to solve that complicated problem.

他不得不绞尽脑汁去解决那复杂。

He puzzled himself over the matter.

他对那件事绞尽脑汁。

She is worrying the problem out.

她正在绞尽脑汁解决这。

All night I have been tossing and turning racking my brains to think what could have possessed the young man to kill himself.

整整一晚辗转反侧, 绞尽脑汁, 想弄明白是什么原因竟能促成这年轻人自杀。