剩余时间
:
扫一扫微信做题更方便
保安考试
1、What does the author say about people's sleeping habits?
2、What do we learn about the Russians regarding sleep?
3、What is the major cause for Europeans' loss of sleep?
4、What is the most probable reason for some rich people to use a device to record their patterns?
5、What does the author imply in the last paragraph?