[lè bù kě jí]   

乐    不    可    极    享乐不可过分。

享乐不可过分,否则乐极生悲。也比喻做事要有限度

One should not pursue pleasure to its extreme

乐极生哀    乐亭大鼓    乐山爱水    乐道安命    乐于助人