你脑子里在想什么？

Nǐ nǎozi lǐ zài xiǎng shénme?

What are you thinking in your mind?

长时间看手机对眼睛和大脑都不好。

Cháng shíjiān kàn shǒujī duì yǎnjīng hé dànǎo dōu bù hǎo.

Looking at your phone for a long time is bad for both your eyes and your brain.

我今天脑子有点儿累，想早点休息。

Wǒ jīntiān nǎozi yǒudiǎnr lèi, xiǎng zǎodiǎnr xiūxi.

My brain is a bit tired today; I want to rest early.