What is the main idea of the passage?

Sleep is active, useful time when the body and brain do vital work (The passage argues that sleep is not wasted time but active, useful work.)

According to the text, what does the brain do during sleep?

It sorts what we learned and stores what is worth keeping (The text says the brain "sorts through what we learned and stores the parts worth keeping.")

In this passage, "repairs" most nearly means

fixes what was damaged (The body "repairs muscles" and "heals small hurts," so repairs means fixes what was damaged.)

Why We Sleep: Level 2 Reading Comprehension Questions

Q: Why do students who sleep well remember more than those who stay up all night?

Sleep helps the brain store what was learned (Since sleep "stores the parts worth keeping," missing sleep loses some of what was learned.)

We spend about a third of our lives asleep, yet many people treat sleep as wasted time. In truth, the body and brain are hard at work while we rest.

During sleep, the body repairs muscles and heals small hurts from the day. The brain does something just as important: it sorts through what we learned and stores the parts worth keeping. This is one reason students who sleep well remember more than those who stay up all night to study. Sleep also clears waste from the brain that builds up while we are awake.

When we do not get enough, we feel it. We think slowly, forget easily, and grow short of temper. A single bad night is not serious, but weeks of poor sleep harm both health and mood. Sleep is not lost time. It is the quiet work that makes the waking hours possible.

Comprehension questions