睡得久≠睡得好：探秘睡眠周期
World Sleep Day falls on March 21.
Our bodies sleep in 90-minute cycles. It means if we sleep 8 hours a night, we will experience five to six cycles each night. 1. The body temperature drops and the heart rate(心率) slows. Next comes deep sleep. 2. This is when your body repairs itself and builds up energy for the day. At this time, your heart rate is at the lowest point. Finally, you get into the rapid eye movement(REM) sleep stage. 3. After the REM sleep stage, the cycle restarts.
Waking up in the “wrong” stage can leave you feeling especially tired. 4. And you shouldn't just start your sleep cycle whenever you want. 5. They think as long as they have 8 hours of sleep, everything will be fine. But in fact, our bodies can tell the time by using light and temperature. That's why sometimes we feel even more tired after oversleeping.
选择合适的句子补全短文,将序号填写在横线上。

根据短文内容,选择正确的答案。
()6. 新考法 学科融合 How does the heart rate change during a sleep cycle?

词汇积累 语法充电
视频精讲 口语朗读
语篇类型: 科普说明
难度星级: ★★★★★
建议用时: /10 min
参考答案: P06

1. A 根据“At first, you enter a light stage of sleep when your muscles relax.”可知,这段里先讲的是睡眠的第一个阶段,肌肉放松,进入浅睡眠状态。故选 A。
2. E 根据“This is when your body repairs itself and builds up energy for the day. At this time, your heart rate is at the lowest point.”可知,这段讲的是深度睡眠阶段,身体修复并储存能量。结合上下文,深度睡眠阶段很难醒来。故选 E。
3. B 根据“It is when most dreaming happens and the heart rate rises.”可知,这段讲的是快速眼动(REM)睡眠阶段,做梦主要发生在这个阶段,心率上升。故选 B。
4. D 根据“Waking up in the ‘wrong’ stage can leave you feeling especially tired.”可知,如果在错误的阶段醒来,会感到特别疲劳,所以醒来的时间很重要。故选 D。
5. C 根据“Many young people go to bed late and get up late.”可知,很多年轻人睡得很晚,起得很晚,这与后面提到的身体通过光线和温度来判断时间相关,解释了为什么睡眠时间足够但仍然感到疲劳。故选 C。
6. B 根据原文第二段描述可知,浅睡眠阶段心率会下降,深度睡眠阶段心率是最低的,REM 阶段心率会升高,选项 B 与文章描述一致。故选 B。