Human beings go through 1. stages during sleep. In the first stage, your muscles relax, your body temperature gets a bit cooler and your heartbeats become 2. . In the next stage, you fall into a light sleep. At this point, you can be 3. up easily. As you enter the third stage, your blood pressure lowers and your body becomes less sensitive to the environment. If you are awakened at the fourth stage of sleep, you're likely to be 4. for a while. The final stage of sleep is called REM sleep. REM stands for “5. eye movement”. REM sleep is when most dreams occur.

A. 1. five 2. slower 3. woken 4. confused 5. rapid