Is that nine hours of sleep thing like mandatory or?

那九个小时的睡眠是强制性的还是？

Teenagers need eight to ten hours of sleep each night.

青少年每晚需要8到10个小时的睡眠。

Getting at least 6 hours of sleep is crucial before an exam.

在考试前一晚最少睡六个小时是非常重要的。

You need to get close to 8 hours of sleep.

你需要接近8小时的睡眠。

Three hours of sleep yesterday. It was a good fight last night.

我昨天只睡了三个小时，昨晚和野火的一战打得很好。

Experts say to try to get around seven hours of sleep each night.

专家建议大家每晚尽量最少睡7小时左右。

Aim for seven to eight hours of sleep per night in addition to naps.

除了午睡之外，尽量保障每晚七到八小时的睡眠。

But for the vast majority of us, we need 7 to 9 hours of sleep.

但事实上对我们大部分人来说，我们需要7到9小时的睡眠时间。

Health experts say most adults need at least seven hours of sleep each night.

健康专家表示，大多数成年人每晚至少需要7小时的睡眠。

Health experts suggest that adults get seven to eight hours of sleep each night.

健康专家建议成年人每晚睡七到八个小时。

Other primates need as many as 14 to 17 hours of sleep.

而其它的动物则需要长达14甚至17个小时。

Many sleep experts say adults should aim for eight hours of sleep a night.

许多睡眠专家说，成年人应该以每晚八小时的睡眠为目标。

The risk climbed as the hours of sleep dropped, with a 53-percent greater injury risk at six hours of sleep.

这一风险会随着睡眠时间的减少而上升，6小时睡眠的损伤风险会增加53%。

Number five, eight hours of sleep.

第五，八小时睡眠。

To function their best, experts say teenagers need at least nine hours of sleep every night.

为了使得身体机能维持最佳状态，专家认为青少年每天至少应该睡9个小时。

So, what is it about getting eight hours of sleep every night that helps improve brain power?

那么，每晚八小时的睡眠是如何帮助提高脑力的呢？

At five hours of sleep, the risk of injury was two times greater.

而如果睡眠时间为5小时，那损伤风险则要高出两倍。

The poll also asked people to report how many hours of sleep they usually get each night.

这项民意调查还要求人们报告他们每晚的睡眠时长。

I always thought she got by, she managed her job, with just four hours of sleep a night.

我一直认为她为了完成工作，每天只睡4个小时。

It takes a week to run this race on no more than six hours of sleep a night!

跑完全程要花一周的时间，而且每晚的睡眠不足六个小时。