Li Ming studies in a high school, and this is his second year. In order to get improved as soon as possible, he decided to study late every night. Usually, he would go to sleep about 11 o’clock, but the pressure made him couldn’t sleep well, so he kept study until 12 o’clock. A month passed, Li Ming realized that he didn’t make progress, instead, he lag behind. He talked to his teacher and the teacher told him that he needed to rest well and took it easy. Only the student slept well would he have the energy to study and focus on his attention. Li Ming did as the teacher said, indeed. It worked, he made progress and he could thought quickly. Sleeping well is the very important way to improve study efficiency.