15 年前
视频简介
该剧讲述由于人类的愚昧，过度的向大自然进行索取，一千多年的时间，宏伟壮丽的夏国国都失去了绿色的屏障。生态环境失去平衡，终于变成了沙漠中的废墟。这是大自然对于人类的惩罚，也对人类敲响了警钟。从此，我国人民踏上了治理环境，植树造林的征程……。NOVA: Mysteries of Sleep Like virtually every other animal, humans need sleep to survive. But why? What do we gain from spending nearly a third of our lives in such a defenseless state? And what's at stake if we sleep poorly? The functions of sleep have long been something of a mystery. But now scientists are peering deep into the brain to see what happens while we snooze. One ...。
标签
科学
