Ancient Roman economy depended on oil.

Pythons need:

If we continually lack sleep, the specific part of our brain that controls language is ........................... .

True sleep lasts approximately ..................... .

Although during REM sleep our breathing rate and blood pressure rise, our bodies 

During the Light Sleep stage:

The brain activity is really high:

After four sleepless days, Randy had a delusion about him being a football celebrity. 

According to Jim Horne, we need to sleep as much as it takes to not be sleepy during the day.

There are four stages of the REM sleep