【#第一文档网# 导语】以下是®第一文档网的小编为您整理的《托福写作高分范文-睡眠革命_托福写作_托福_智课教育官网》，欢迎阅读！
智课网TOEFL备考资料 托福写作高分范文-睡眠革命_托福写作_托福_智课教育官网 您当前的位置 » 智课教育官网 » 托福 » 托福写作 » 文章正文 出国英语考试有哪些 雅思6.5是什么水平 雅思阅读评分标准 托福阅读评分标准 雅思和托福的区别 托福写作成绩提升有很多方法，背诵一些托福写作范文中的句子也是非常有效的方法之一，一起来看看托福写作高分范文吧! Evolution of sleep Sleep is very ancient. In the electroencephalographicsense we share it with all the primates and almost allthe other mammals and birds: it may extend back asfar as the reptiles. There is some evidence that the two types of sleep,dreaming and dreamless, depend on the life-style ofthe animal, and that predators are statistically muchmore likely to dream than prey, which are in turnmuch more likely to experience dreamless sleep. Indream sleep, the animal is powerfully immobilized and remarkably unresponsive to externalstimuli. Dreamless sleep is much shallower, and we have all witnessed cats or dogs cocking theirears to a sound when apparently fast asleep. The fact that deep dream sleep is rare amongpray today seems clearly to be a product of natural selection, and it makes sense that today,when sleep is highly evolved, the stupid animals are less frequently immobilized by deep sleepthan the smart ones. But why should they sleep deeply at all? Why should a state of such deepimmobilization ever have evolved? Perhaps one useful hint about the original function of sleep is to be found in the fact thatdolphins and whales and aquatic mammals in genera seem to sleep very little. There is, by andlarge, no place to hide in the ocean. Could it be that, rather than increasing an animal’svulnerability, the University of Florida and Ray Meddis of London University have suggestedthis to be the case. It is conceivable that animals who are too stupid to be quite on their owninitiative are, during periods of high risk, immobilized by the implacable arm of sleep. Thepoint seems particularly clear for the young of predatory animals. This is an interesting notionand probably at least partly true. 以上是托福写作高分范文，更多托福信息可以关注智课教育托福频道。 本文来源：https://www.dywdw.cn/74ddeb9a852458fb770b56d8.html
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2022-04-26
