不停地熬夜是很愚蠢的做法，对身体伤害很大。

Bù tíng de áoyè shì hěn yúchǔn de zuòfǎ, duì shēntǐ shānghài hěn dà.

Staying up late all the time is a very foolish practice and greatly harms the body.

他不是坏人，只是有时候会做出一些愚蠢的事情。

Tā bú shì huàirén, zhǐshì yǒu shíhou huì zuòchū yìxiē yúchǔn de shìqing.

He is not a bad person; he just sometimes does some stupid things.

我当时做了一个非常愚蠢的决定。

Wǒ dāngshí zuò le yí gè fēicháng yúchǔn de juédìng.

At that time I made a very stupid decision.