Read the paragraph. Read the question and choose the correct answer.
Stage one is light sleep, and a human's body begins to feel a little drowsy.
This stage only lasts from 1 to 10 minutes. If you wake during this stage, you will feel like you have never slept at all. Your breathing slows down, there is a regular heartbeat, but blood pressure and brain temperature decrease. During stage one, a hypnic jerk like a twitch may occur, and you may wake. If you don't get enough sleep, you may doze off at the desk and may suddenly awake during the class. You may feel as if you're falling.
Which statement is TRUE, according to the text?

• Stage one can continue for 20 minutes.
• Stage one isn't your deep sleep.
• During stage one of sleep, your body temperature can increase.
• Stage one is the main part of your sleep.