In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
The strangers in your dreams are actually people that you've seen in real life.
50
Cows can sleep standing up, but they can only dream lying down.
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The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Dieters who sleep more take off more fat that those who sleep less.
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