A strange thing happens to nearly everybody at night. They ______ the lights，pull up the covers and close their eyes. After they sleep for six or seven ______，they wake up again. It sounds very strange，doesn't it？
Sleep puzzles（使困惑）science all the time. _____ and doctors would like to talk about why one can't fall asleep. They are not so sure ______ causes sleep.
You will sleep the best both ______ you are in good health and when you don't eat too much or too little. No worries and a comfortable place to sleep are ______，too. They advise against two in one bed.
Strange things ______ during sleep. For example，you often move during your sleep. You should feel ______if you didn't move. You also ______. Part of your brain is still _______ when you dream.
Don't worry if you dream. Some great stories and poems were finished while their writers were dreaming.
| 【小题1】 | | A．turn on | B．turn off | C．turn up | D．turn down |
|
| 【小题2】 | | A．seconds | B．hours | C．days | D．months |
|
| 【小题3】 | | A．Scientists | B．Nurses | C．Artists | D．Inventors |
|
| 【小题5】 | | A．after | B．when | C．before | D．until |
|
| 【小题6】 | | A．pleased | B．possible | C．important | D．funny. |
|
| 【小题7】 | | A．happen | B．happens | C．happened | D．happening |
|
| 【小题8】 | | A．hungry | B．tired | C．relaxed | D．worried |
|
| 【小题9】 | | A．sleep | B．wake up | C．think | D．dream |
|
| 【小题10】 | | A．busy | B．asleep | C．awake | D．sleepy |
|
