Question

【题目】阅读理解。
Have you ever experienced the feeling of falling as you start to fall asleep? Sometimes you may come to realize this feeling. If so, don't worry. Many people have felt the same thing.
In fact, these muscle twitches (肌肉抽搐) in the arms, legs or other parts of the body are called hypnic jerks (入睡抽动) or sleep starts. And they are very common. Up to 70 percent of people experience them sometimes, Huffington Post reported. But what causes it?
There are some theories(理论). Some scientists believe that the feeling of falling comes from the body relaxing itself, especially if the person is anxious or unable to get comfortable. As you're about to sleep, your muscles become relaxed. But your brain stays awake. It misunderstands the relaxing of your muscles as a sign that you're falling.
Then the brain jerks the body awake as if it's trying to protect you.
Other scientists believe that different phases of sleep might cause the hypnic jerks. When we sleep, we experience two phases: non-rapid eye movement (NREM) and rapid eye movement (REM). During REM, our heart rate (心率), breathing and nervous system can act irregularly (不规律地). If the body experiences flashes (一瞬间) of REM while entering sleep, these irregularities could cause twitches.
If you don't want to experience hypnic jerks, scientists have some suggestions. When you become deeply relaxed, you can learn how to reconnect slowly by moving your fingers and toes a little bit. Then start to move your head and open your eyes, while being aware of yourself as you get out of the relaxed state.
But experts agree that hypnic jerks, though sometimes scary, are harmless. If it wakes you up, simply roll over and go back to sleep. But keep in mind: a caffeinated (含咖啡因的) drink, exciting evening activities or stress may make hypnic jerks happen more often.
（1）The third paragraph mainly tells us_____________.
A.there are all kinds of theories about hypnic jerks
B.different phases of sleep might cause hypnic jerks
C.People sometimes get anxious or uncomfortable
D.the feeling of falling comes from the body relaxing itself
（2）How many theories on what causes hypnic jerks are mentioned?
A.Two
B.Four
C.Three
D.Five
（3）Which of the following can make hypnic jerks happen more often?
①Drinking caffeinated drink ②Singing songs for a long time before sleep
③Too much stress ④reading a book quietly
A.①②③
B.①②④
C.②③④
D.①③④
（4）What is the best title?
A.How to Experience Hypnic Jerks
B.What causes Hypnic Jerks
C.Feelings of Falling While Going to Sleep
D.Sleeping Is Good for Our Health

Answer 1

【答案】
（1）D
（2）A
（3）A
（4）C
【解析】本文叙述了科学家对于人们睡觉的时候有坠落的感觉的两种不同的看法。一是身体的坠落的感觉来自身体自身的放松；二是不同阶段的睡眠会引起入睡抽动。
（1）段落大意题。根据Some scientists believe that the feeling of falling comes from the body relaxing itself这是中心句，身体的坠落的感觉来自身体自身的放松。故选D。
（2）细节理解题。根据 Some scientists believe that the feeling of falling comes from the body relaxing itself； Other scientists believe that different phases of sleep might cause the hypnic jerks.可知，有两种观点：一是身体的坠落的感觉来自身体自身的放松；二是不同阶段的睡眠会引起入睡抽动。故选A。
（3）细节理解题。根据But keep in mind: a caffeinated (含咖啡因的) drink, exciting evening activities or stress may make hypnic jerks happen more often.可知，含咖啡因的饮料，令人刺激的活动如：睡前唱歌；太多的压力等。故选A。
（4）标题归纳题。根据短文主要叙述的是科学家对于人们睡觉的时候有坠落的感觉的不同看法。故选C。