有哪些经典好看的电视剧

视频简介

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 ...。These child prodigies of the animal kingdom have feathers and beaks – and very special skills! The Keas of New Zealand are the only parrots that live in snowy mountain areas. They like testing their brains, solving puzzles and challenging tourists: they unscrew bottle-tops, dismantle windscreen wiper blades and tear open rucksacks. They seem so determined you’d think they have ...。