你的睡眠充足吗？看专家关于睡眠的建议
We spend about one-third of our lives sleeping. Our body needs sleep to stay healthy. Not getting enough sleep may make us sick.
Sleep and our immune(免疫的) system
The immune system protects the body from diseases and infections. Not getting enough sleep hurts this protective system. The Mayo Clinic is a nonprofit research hospital in the United States. Its website explains that when we sleep, our body releases proteins(蛋白质) that support sleep and help us fight infections. The Mayo Clinic says the study shows that the immune system works best when the body gets enough sleep.
How much sleep is enough?
To stay in good health, experts at the Mayo Clinic say that adults should get 7 to 8 hours of sleep a night. Teenagers need 9 to 10 hours. And school-aged children may need more than 10 hours of sleep a night. Experts say the quality and quantity of our sleep become poor as we get old. They say the process begins in our 30s. By the time we reach our 50s, the average person has lost 50 percent of their ability to have a peaceful sleep.
How to improve your sleep
People can do things to get better sleep. Health experts suggest doing exercise and avoiding working on computers and electronic devices(设备) before bed. A cool room is also a better environment for sleeping.
1. According to the Mayo Clinic, enough sleep may _________.
A make the immune system work better
B prevent our body from diseases
C hurt the immune system
D release less protein
解析：选A。A 细节理解题。根据第二段The Mayo Clinic says the study shows that the immune system works best when the body gets enough sleep.可知梅奥诊所表示，这项研究表明，当身体得到足够的睡眠时，免疫系统工作得最好。选项A最符合文意，故选A。
2.Tom is 7 years old, and he needs at least _________ of sleep.
A 6 hours
B 8 hours
C 9 hours
D 10 hours
解析：选D。D 推理判断题。根据第三段And school-aged children may need more than 10 hours of sleep a night.可知，7岁的Tom需要十个小时以上的睡眠，即至少需要10个小时的睡眠，故选D。
3.You can improve your sleep by _________.
A playing computer games before bed
B watching TV with your family
C taking a walk after dinner
D sleeping in a hot room
解析：选C。C 推理判断题。根据第四段可知，锻炼有助于睡眠，凉爽的房间也有助于睡眠，但要避免在睡前看电脑和电子设备，结合选项可知饭后散步属于锻炼，故选C。
4.What can be the best title of the passage?
A How Much Sleep Is Enough?
B Are You Getting Enough Sleep?
C How to Improve Our Sleep?
D Sleep And The Immune System.
解析：选B。B 主旨大意题。根据全文可知，A、C、D三项均属于文章的部分内容，并不能概括全部，全文围绕睡眠展开，给出了一些相关的知识和建议，B选项最符合文意，故选B。
5.Where may you read the passage?
A In a fashion magazine.
B In a story book.
C On a health website.
D In a postcard.
解析：选C。C 文章出处题。全文围绕睡眠展开，给出了一些相关的知识和建议，属于健康版块，故可以从健康网站上看到，故选C。