youdao

We experience some deep, quiet sleep and some active sleep, which is when dreams happen.

我们会经历一些深层且安静的睡眠以及一些活跃的睡眠，而活跃的睡眠时期正是做梦的时候。

youdao

Over time, not having enough sleep—especially deep and REM sleep—can cause one to become sick more easily.

随着时间的推移，睡眠不足会让人更加容易生病，尤其是深度睡眠和快速眼动睡眠时间不足时。

youdao

Suddenly I was in deep,dreamless, peaceful sleep.

VOA: special.2010.07.10

But think of the various periods during the night in which you are in a deep, deep dreamless sleep.

但请设想你处在这样的夜晚,你处于熟睡，安枕无梦。

耶鲁公开课 - 死亡课程节选

It's not that He simply wakes up those in a deep, deep sleep.

他并不只是将他们从沉睡中唤醒。

耶鲁公开课 - 死亡课程节选

Total deep sleep decreases from nearly 20% of a normal nights sleep for those under 25 to less than 5% for those over 35.

BBC: Sleep linked to ageing

That part of the brain is essential for entering deep sleep, but with age the region degrades.

BBC: Boosting sleep 'may slow memory rot'

Early one Sunday morning, the shrill reverberating sound of my home phone woke me from a deep sleep.

FORBES: A Rolls Royce Drove My Overnight Success