睡眠是一种周期性的生理现象，是人类生命活动的一个重要方面。儿童由于神经发育尚不成熟，身体内每一个细胞的增加都需要能量。因此，儿童的能量不仅要消耗在活动上，而且，大部分还用在“建筑”自身上。对儿童来说，睡眠同饮食、空气一样重要，它既能“节能”，又可以使能量 Sleep is a cyclical physiological phenomenon, is an important aspect of human life activities. Children are not mature because of nerve development, the body needs an increase in energy for every cell. Therefore, children’s energy is not only consumed in the activities, but most are also used in the “building” itself. For children, sleep is as important as diet and air, and it “conserves energy” as well as energy