Claparede also had an explanation for how long we sleep: we wake up when we have had enough.

claparede还解释了人类睡眠的长短：我们睡够了就会醒来。

youdao

Claparede also had an explanation for how long we sleep: we wake up when we have had enough.

claparede还解释了人类睡眠的长短：我们睡够了就会醒来。

youdao