1. In general, it is appropriate to sleep at night from 10: 30 to 1 1. Second, the theory of health preservation: the six hours from 2 1:00 to 3:00 am the next day are winter. The so-called "hiding in winter" means that sleeping at this time is the most scientific. After falling asleep, the functions of various organs of the human body begin to recuperate and recover after a day's work. If it is well refrigerated in winter, it will grow better in the next summer, that is, it will be more energetic to work the next day. So generally we can sleep from 10:30 at night to 6:30 the next day. Third, the quality of sleep is very important. So try not to get too excited 1-2 hours before going to bed at night, otherwise it will be difficult to fall asleep at night and dream, which will affect the quality of sleep. Fourth, adequate and quality sleep can improve learning efficiency and quality.