Evolution of sleep英语六级作文
sleep is very ancient. in the electroencephalographic sense we share it with all the primates and almost all the other mammals and birds: it may etend back as far as the reptiles. there is some evidence that the two types of sleep, dreaming and dreamless, depend on the life-style of the animal, and that predators are statistically much more likely to dream than prey, which are in turn much more likely to eperience dreamless sleep. in dream sleep, the animal is powerfully immobilized and remarkably unresponsive to eternal stimuli. dreamless sleep is much shallower, and we have all witnessed cats or dogs cocking their ears to a sound when apparently fast asleep. the fact that deep dream sleep is rare among pray 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 sleep than the smart ones. but why should they sleep deeply at all? why should a state of such deep immobilization ever have evolved? perhaps one useful hint about the original function of sleep is to be found in the fact that dolphins and whales and aquatic mammals in genera seem to sleep very little. there is, by and large, no place to hide in the ocean. could it be that, rather than increasing an animal's vulnerability, the university of florida and ray meddis of london university have suggested this to be the case. it is conceivable that animals who are too stupid to be quite on their own initiative are, during periods of high risk, immobilized by the implacable arm of sleep. the point seems particularly clear for the young of predatory animals. this is an interesting notion and probably at least partly true.
-
2023年6月英语六级听力长对话的技巧
长对话由于篇幅较长,想要听一遍就将主要内容都记清楚,几乎是不可能的。下面本站小编为大家搜索整理了关于英语六级听力长对话的技巧,欢迎阅读积累,希望对大家备考有所帮助!想了解更多相关信息请持续关注我们应届毕业生考试网。6月英语六级听力长对话的技巧1考生只...
-
英语六级考试口语话题指导练习
聪明在于学习,天才在于积累。所谓天才,实际上是依靠学习。以下是小编为大家搜索整理的'英语六级考试口语话题指导练习,希望能给大家带来帮助!更多经常内容请及时年关注我们应届毕业生考试网!It'sveryhottoday,isn'tit?Isn'tithottoday?Today'sas...
-
2022年大学英语六级词汇语法辅导试题及答案
大学英语六级考试是由国家统一出题的',统一收费,统一组织考试,用来评定应试人英语能力的全国性的考试,每年各举行两次。不知道大家对大学英语六级了解多少?以下是小编为大家收集的大学英语六级词汇语法辅导试题及答案,仅供参考,欢迎大家阅读。大学英语六级词汇语法辅...
-
精选大学英语六级作文(通用29篇)
在我们平凡的日常里,大家对作文都不陌生吧,作文是从内部言语向外部言语的过渡,即从经过压缩的简要的、自己能明白的语言,向开展的、具有规范语法结构的'、能为他人所理解的外部语言形式的转化。那么问题来了,到底应如何写一篇优秀的作文呢?以下是小编帮大家整理的大...
相关文章
- 英语阅读:Life is inevitable consequence of physics
- Jolie drops battle over perfume named Shilohy英语作文
- GRE英语写作范文:Evolution of sleep
- 评教研课Unit One Will people have robots?范文
- Health in developing countries大学六级英语写作范文
- Unit1Willpeoplehaverobots的初二年级下册英语知识点
- 新目标八年级英语下册Unit 1 Will people have robots教案
- 英语阅读范文参考:LovePeopleInAllKindsOfWeather
- 人教版八年级上册英语Unit7Willpeoplehaverobots随堂检测题
- 初中英语《Unit 1 Will people have robots》教学设计