Dreams can happen in any of the four stages of sleep. The most memorable and clearest dreams happen in the last stage of sleep (also known as REM sleep). The sleep cycle repeats about four to five times every night. So you can see how a person has several different dreams in one night. Most people only remember dreams that happen closer to the morning when they are about to wake up. That you can’t remember those dreams does not mean they never happened.
The stages in the sleep cycle are organized by the changes in different brain activities.

Stage 1: You are entering into light sleep. In this stage, your eyes move rapidly. We call this NREM. The body gets relaxed and your body temperature lowers. Your heart rate lowers, too. The body is preparing to enter into deep sleep.
Stage 2: Also characterized by NREM. In this stage, the body temperature and heart rate drop again. You are completely asleep.
Stage 3: Still in the NREM stage, this is a deeper sleep still.
Stage 4: In this stage of sleep, your eyes move back or forward. We call it REM sleep. This stage happens at about 90-100 minutes after the beginning of sleep. Your blood pressure rises, heart rate speeds up. The majority of your dreams happen in this stage.
These stages repeat themselves throughout a night’s sleep.
Dreams can happen in ___________.
A. Stage 1 and 2           B. Stage 3 and 4            C. every stage
Which of the following sentences is TRUE according to the passage?
A. These stages will happen once or twice one night.
B. Most people only remember the dreams that happen when they are about to wake up.
C. If one can’t remember his dreams, he never dreams at all.
What will happen in Stage 2?
A. Eyes move rapidly.   B. People enter into light sleep.    C. Heart rate drops.
The first REM sleep happens about ___________ after the starting of sleep.
A. 1 to 2 hours                     B. 2 to 3 hours                     C. 10 minutes
The passage is mainly about ___________.
A. the stages of sleep     B. types of dreams         C. remembering dreams