have (got) something on the brain

(informal)be obsessed with something

(非正式)萦绕于脑际，念念不忘

John has cars on the brain.

约翰心里老是惦记着汽车。

beat (one's) brains (out)

&I{Informal} To exert or expend great mental effort

【非正式用语】 绞尽脑汁，大费脑筋：用光或耗尽极大的智力努力

She beat her brains out during the examination.

在考试中她绞尽脑汁

on the brain

Obsessively in mind

热衷于，念念不忘：一心想着某事

The coach has winning on the brain.

教练一心想着取得胜利

pick (someone's) brain 或 pick (someone's) brains

To explore another's ideas through questioning.

思想剽窃：在解决问题中使用别人的想法

rack (one's) brain【非正式用语】

To think long and hard

冥思苦想：长时间艰苦地思考

I racked my brain for hours trying to recall her name.

几小时来我苦苦思索以期回想起她的名字