1. (2020·即墨模拟) 阅读下面短文，按要求完成各项任务。

    A strange thing happens to nearly everybody. At night, people turn off the lights, pull up the covers and close their eyes. Six or seven sleeping hours later, they wake up again. Strange, isn't it?

    Sleep ①puzzles science. Scientists and doctors would rather talk about why one can't fall asleep. They are not sure what causes sleep. The best conditions for sleep are good health and meal neither too big nor too small. No worries and a comfortable place are important, too.

    Strange things happen during sleep. For example, you move often. You would feel tired if you didn't. You also dream. Part of your brain is still awake when you sleep. Dreaming happens when the memory and imagination in parts of your brain are still awake. Experiments have shown most of us dream in color. Bad dreams may be caused by stomachache. Don't worry if you dream. Some great stories and poems were begun while their writers slept.

1. （1） 根据短文内容，猜测①处划线单词puzzle的意思。

   A . 困惑 B . 谜语 C . 解释
3. （2） 列举出文章中提到的好睡眠需要的条件。

   ① good health  ②   ③  ④ a comfortable place

5. （3） 回答问题。Why do people dream while they are sleeping?
7. （4） 从文章中找出与Stomachache may cause bad dreams.意思相同或相近的句子。
9. （5） 根据文章内容，给本文拟一个合适的标题。