His first sleep after those 11 days lasted just 14 hours.

在这11天之后，他的第一觉只睡了14小时。

youdao

This was during the first deep sleep period, the researchers said.

研究人员说，这发生在第一次深度睡眠期间。

youdao

To better understand breathing during sleep, it is, however, helpful to first understand how respiration works in general.

然而，为了更好地理解睡眠中的呼吸，首先了解呼吸的一般工作原理是有帮助的。

youdao

But here is something that scientists now know: A team led by Professor Fu has reported the first genetic link to how much sleep we need.

VOA: special.2009.08.26

Well, first there's a distinction, a distinction between real dreams versus sleep thought.

首先，我们要区分，真正的梦和半睡半醒的想法。

耶鲁公开课 - 心理学导论课程节选

First of all,notice the obvious point that sometimes people die in their sleep,unexpectedly.

首先，有时人是在睡梦中无预兆地死去。

耶鲁公开课 - 死亡课程节选

"It is my fourth visit to Japan and it is the first timeI sleep well, " Waseige said.

BBC: Belgians shake off injuries

By the 1920s the idea of a first and second sleep had receded entirely from our social consciousness.

BBC: The myth of the eight-hour sleep

Ekirch found that references to the first and second sleep started to disappear during the late 17th Century.

BBC: The myth of the eight-hour sleep