Throughout the night, people alternate between passive and active sleep.

整个夜晚，人们被动和主动之间轮流睡觉。

Each night we alternate between two kinds of sleep: active sleep and passive sleep.

每间两种睡眠：主动和被动睡眠晚上我们轮流睡觉。

The passive sleep gives our body the rest that's needed and prepares us for active sleep, in which dreaming occurs.

被动睡眠使我们的身体休息，我们需要准备主动睡眠，其中做梦发生。

Ground squirrels are normally active by day and sleep at night.

地松鼠一般白天活跃晚上睡觉。

REM sleep is termed 'active' sleep.

快速眼动睡眠称作“主动”睡眠。