How long do teenagers need to sleep?

青少年需要睡多久？

youdao

I need to sleep. That's all.

我需要睡会儿觉，就会好了。

youdao

All people need to sleep.

所有人都需要睡觉。

youdao

Studies have shown that over time, most humans need eight to eight and a half hours of sleep for the best health.

VOA: special.2009.08.26

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

"I wanted to get it done because I need to sleep, " he said.

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Do you need to sleep a lot to function well at work?

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America is the first society in the world that has tried to organise itself on the assumption that human beings do not need to sleep.

ECONOMIST: A hard day��s night