Why Do We Sleep?
Discover how sleep helps your body and brain, what affects your rest, and what we still do not know about dreams.
Preview
Questions with solutions-
1. 정답을 선택해 주세요。
Which change is most likely after too little sleep?
Maya stayed up very late. This morning, she keeps losing her place while reading.
- It becomes harder to focus.
- She needs less sleep the next night.
- She feels more alert all day.
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- It becomes harder to focus.
Too little sleep can affect attention, making everyday tasks harder to complete.
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2. 정답을 선택해 주세요。
How is sleep different from switching off a machine?
While you sleep, you keep breathing and your brain continues to work.
- Every part of the body stops working.
- The body stays active in some ways.
- The brain works only when you dream.
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- The body stays active in some ways.
Sleep is an active process: your brain and body still carry out important jobs.
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3. 빈칸을 채워 주세요。
Sleep supports the body's recovery after daily activity.
During sleep, the body can ___ damaged tissue.
- weaken
- damage
- repair
Think about how the body recovers.
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During sleep, the body can repair damaged tissue.
This is one reason good sleep matters after exercise.
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4. 정답을 선택해 주세요。
Why does enough sleep matter for staying healthy?
Sleep supports the immune system, which helps protect the body from illness.
- It supports the body's defenses.
- It guarantees that you will never get sick.
- It removes the need for vaccines.
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- It supports the body's defenses.
Sleep supports your defenses, but it cannot prevent every illness.
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5. 정답을 선택해 주세요。
What does the body's internal clock help control?
Your body follows a daily rhythm, even without a clock on the wall.
- The exact time that everyone must go to bed.
- The ability to stay awake without needing sleep.
- When you tend to feel sleepy or awake.
Think about changes that repeat each day.
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- When you tend to feel sleepy or awake.
People's daily rhythms can differ, so not everyone feels sleepy at the same time.
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6. 빈칸을 채워 주세요。
Morning daylight tells your body clock that the day has begun.
Bright morning light is a signal that it is time to be ___.
- asleep
- awake
- dreaming
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Bright morning light is a signal that it is time to be awake.
Outdoor daylight is usually brighter than indoor light, even on cloudy days.
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7. 정답을 선택해 주세요。
How can sleep help with learning the speech?
You practice a short speech and then get a good night's sleep.
- It can teach you parts you never practiced.
- It can remove your need to practice again.
- It can help strengthen your memory of it.
Think about what happens to information you have already learned.
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- It can help strengthen your memory of it.
Sleep helps the brain build memories, but it does not replace practice.
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8. 빈칸을 채워 주세요。
Lighter sleep, deeper sleep, and REM sleep repeat during the night. Together, these stages form a sleep ___.
- cycle
- habit
- problem
The stages return rather than happening only once.
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Lighter sleep, deeper sleep, and REM sleep repeat during the night. Together, these stages form a sleep cycle.
The amount of time spent in each stage changes across the night.
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9. 정답을 선택해 주세요。
What can happen during REM sleep?
REM is short for "rapid eye movement." It is one stage of sleep.
- The eyes stay completely still.
- The eyes move behind closed eyelids.
- The person must open their eyes.
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- The eyes move behind closed eyelids.
During REM sleep, most of the body's muscles are usually very relaxed.
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10. 정답을 선택해 주세요。
Why might Noah find it harder to fall asleep?
Noah drinks coffee late in the evening. He plans to go to bed soon.
- Caffeine helps the body enter deep sleep faster.
- Coffee's effect always ends after a few minutes.
- Caffeine can keep him alert for hours.
Coffee's effects can last beyond the time spent drinking it.
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- Caffeine can keep him alert for hours.
Caffeine can block some of the brain's signals that make you feel sleepy.
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11. 정답을 선택해 주세요。
What is the most likely reason Ella is not sleepy?
Ella takes a long nap in the early evening. At her usual bedtime, she does not feel ready to sleep.
- The nap reduced her need for sleep for a while.
- Any nap permanently damages the body's clock.
- Sleeping earlier makes the body need more sleep immediately.
She has already had some rest.
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- The nap reduced her need for sleep for a while.
Your need for sleep builds while you are awake and falls while you sleep.
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12. 정답을 선택해 주세요。
What is the safer response?
Lena feels sleepy while driving. She thinks opening a window will make it safe to continue.
- Keep driving with cold air on her face.
- Stop in a safe place and get some sleep.
- Keep driving and rely on loud music.
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- Stop in a safe place and get some sleep.
Cold air and loud music do not reliably prevent a tired driver from falling asleep.
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13. 정답을 선택해 주세요。
Why might this person's sleep still be poor?
A person feels sleepy after drinking alcohol and falls asleep quickly.
- Falling asleep quickly always prevents waking later.
- Alcohol removes the body's need for deep sleep.
- Alcohol can cause more waking later in the night.
Falling asleep and staying asleep are different.
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- Alcohol can cause more waking later in the night.
Feeling sleepy does not always lead to good-quality sleep.
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14. 정답을 선택해 주세요。
What does Sam's experience suggest about good sleep?
Sam spends plenty of time in bed but wakes often. The next day, Sam still feels tired.
- Sleep quality matters as well as sleep time.
- Time in bed always equals time asleep.
- Waking often always means someone has slept too much.
Consider both the length of the night and how it went.
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- Sleep quality matters as well as sleep time.
Frequent waking can break up sleep, even during a long night.
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15. 정답을 선택해 주세요。
Which statement best matches what we know about dreams?
Dreams may help us deal with feelings or explore situations. Scientists are still studying these ideas.
- All dreams are warnings about future events.
- The exact purpose of dreams is still uncertain.
- Every dream has one clear meaning for everyone.
Notice the difference between a possible explanation and a proven fact.
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- The exact purpose of dreams is still uncertain.
We know many things about sleep, but ideas about why we dream are still being tested.