الكويزات - قراءة المقال
Read the following passage and then answer the questions,

.below

Many people wonder: Why do we sleep? Why do we dream?

They ask

themselves the purpose, or reason. There are many theories, or

opinions

.about this , but scientists don’t know if these ideas are correct

One theory of sleep says that during the day, we need to

sleep to make new chemicals and repair, or fix our bodies. This

theory is

called the “ Repair Theory”. One piece of evidence for this

theory is

that our bodies produce more of growth hormone while we

.sleep

Another theory is that the purpose of sleep is to dream.

Dreaming

occurs only during one stage , or period, of sleep ( Rapid Eye

movement- REM )sleep. REM sleep occurs about 90 minutes

and last

for about 20 minutes. Some scientists believe that REM sleep

helps us

.to remember things, but others don’t believe and don’t agree