头脑清醒

qīng kuài de sàn sàn bù mǎ shàng jiù néng shǐ rén tóu nǎo qīng xǐng

轻快地散散步马上就能使人头脑清醒。

A brisk walk will soon blow the cobwebs away.

wǒ cháng cháng bù zhī dào nǐ shì bù shì tóu nǎo qīng xǐng

我常常不知道你是不是头脑清醒。

I often wonder whether you've got your head screwed on.