四、阅读短文,选择正确的答案。
情境导入:手机在给人们的生活带来便利的同时,也影响着人们的睡眠。彼得深受其害,他正努力寻求解决办法。
Do you play with your smartphone before bedtime(就寝时间)? You may want to read a book in- stead. According to a study, looking at screens at night can cause(导致) us to sleep poorly(糟糕地).
In the evening, our bodies make melatonin(褪黑素). Melatonin helps us feel sleepy and relaxed. It is an important part in our sleep cycle(周期). Our electronic(电子的) screens stop that cycle from working normally. Phones, computers and TVs make blue light. Blue light stops our bodies from mak- ing melatonin. Even just a little bit of blue light can have an effect(影响). Eight minutes of blue light can keep your brain "awake" for another hour, according to the study. Your brain won't have a good rest.
It's even worse if you play an exciting game before bedtime. Games make our hearts beat(跳动) faster, so we have a harder time falling asleep. Then, when we fall asleep, we don't get as much "deep sleep" as we need. Use these tips(提示) to get a good night's sleep:
Take a warm shower or read a book.
Sleep in a dark, quiet room that is not too warm nor too cold.
Count sheep. It's the oldest trick(技巧), but it can actually work!
Don't eat a big meal or have coffee. Instead, drink milk.
Don't run around or exercise three hours before bedtime.
() 1. What can we learn about melatonin?
A. It stops our sleep cycle from working well. B. It helps us feel sleepy and relaxed.
C. Too much of it makes us sleep poorly. D. It makes us feel hungry and tired.
() 2. What does the underlined word "normally" in paragraph 2 mean?
A. 不同地 B. 正常地 C. 简单地 D. 困难地
() 3. doesn't affect our sleep.
A. Looking at screens at night B. Playing an exciting game
C. Drinking coffee D. Taking a warm shower
() 4. The writer gives tips on getting a good sleep.
A. three B. four C. five D. six
() 5. The passage is mainly about .
A. how to get a good night's sleep
B. why melatonin is an important part in our sleep cycle
C. how playing with smartphones causes poor sleep and tips for a good sleep
D. why we can't play an exciting game before bedtime

1.B 2.B 3.D 4.C 5.C

【分析】
1. 第1题是细节理解题，需定位原文中关于褪黑素（melatonin）的描述，匹配对应选项；
2. 第2题是词义猜测题，结合上下文语境推断划线词“normally”的含义；
3. 第3题是细节理解题，需找出不影响睡眠的行为，对应原文的改善睡眠建议；
4. 第4题是细节理解题，需统计文中给出的改善睡眠提示的数量；
5. 第5题是主旨大意题，需归纳全文的核心内容。
【解析】
1. 根据原文第二段“In the evening, our bodies make melatonin. Melatonin helps us feel sleepy and relaxed.”可知，褪黑素的作用是帮助我们感到困倦和放松，A选项是电子屏幕的作用，C选项是蓝光的影响，D选项与褪黑素无关，故答案为B；
2. 由第二段“Our electronic screens stop that cycle from working normally.”可知，电子屏幕干扰睡眠周期，“normally”意为“正常地”，故答案为B；
3. 文中改善睡眠的建议中，“Take a warm shower”是有益睡眠的行为，A（夜间看屏幕）、B（玩刺激游戏）、C（喝咖啡）均会影响睡眠，故答案为D；
4. 文中给出的改善睡眠提示共5条，分别是：①洗热水澡或读书；②睡在黑暗安静、温度适宜的房间；③数羊；④不吃大餐或喝咖啡，喝牛奶；⑤睡前三小时不跑动或锻炼，故答案为C；
5. 全文先阐述玩手机（看屏幕、玩游戏）导致睡眠差的原因，再给出改善睡眠的建议，A选项仅为部分内容，B、D选项过于片面，故答案为C；
【答案】
1.B 2.B 3.D 4.C 5.C
【知识点】
英语阅读理解、细节理解、主旨大意
【点评】
本题围绕手机对睡眠的影响及改善睡眠的建议展开，考查学生的细节查找、词义推断和主旨归纳能力，题型基础，贴近生活，学生通过仔细阅读原文即可完成解答。
【难度系数】
0.6