During the day, we work hard like bees. But do you know our bodies are busy too while sleeping at night?
11:00 pm Better Lock the Doors
To find the most comfortable position, some people sleep on their backs or stomachs. Most people curl up and lie on the side like a baby. Others take more unusual positions, such as on elbows(手肘) and knees or completely covered in the sheets.
During the first few hours of the night, some behaviors can be caused by the disagreement between your brain and body. For example, the brains of sleepwalkers want to stay awake, while their bodies are in a deep sleep. So most sleepwalkers walk around and return to bed without waking up.
4:00 am Dare to Dream
Your sweetest-or scariest-dreams usually happen in the last hours of sleep. If you awaken in the middle of a dream, you might find it difficult to move for a moment. Certain parts of your brain have shut down, stopping messages going to the muscles(肌肉) and disabling the body for a time.
Dreams may seem foolish, but some cultures believe they are real events happening to a person's soul during sleep. Others use their dreams to solve the problems of daily life. 7:00 am
Time to wake up, but wait, your arm can't feel anything. As you begin to move, an uncomfortable feeling floods" down from your shoulder. When pressure on your arm stops sending messages to the brain, your arm loses all feelings. As the pressure is reduced and messages sending restarts, uncomfortable feelings appear. So don't worry if you wake up and your arm is still "asleep". It'll be wide awake in a moment.
B . 
C . 
D . 
