编辑点评: 研习GRE作文考试的优秀范文不仅可以学到有用的词汇和句子,更能从中学习逻辑的构建方式和作文框架的结构等内容,这里为大家提供GRE的范文,希望对同学们的备考有所帮助。
Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only within a narrow range around 37C;a departure of a few degrees from this value seriously impairs their functioning. Even though cells can survive wider fluctuations the integrated actions of bodily systems are impaired. Other animals have a wider tolerance for changes of bodily temperature.
For centuries it has been recognized that mammals and birds differ from other animals in the way they regulate body temperature. Ways of characterizing the difference have become more accurate and meaningful over time, but popular terminology still reflects the old division into warm-blooded and cold-blooded species; warm-blooded included mammals and birds whereas all other creatures were considered cold- blooded.
As more species were studied, it became evident that this classification was inadequate. A fence lizard or a desert iguana-each cold-blooded----usually has a body temperature only a degree or two below that of humans and so is not cold. Therefore the next distinction was made between animals that maintain a constant body temperature, called home0therms, and those whose body temperature varies with their environments, called poikilotherms. But this classification also proved inadequate, because among mammals there are many that vary their body temperatures during hibernation.
Furthermore, many invertebrates that live in the depths of the ocean never experience change in the depths of the ocean never experience change in the chill of the deep water, and their body temperatures remain constant.
名师解析:如何攻克雅思听力中的电话号码
浅谈雅思听力考试的特点和学习方法
雅思听力考试答题规律
雅思听力考前一周如何冲刺备考
雅思听力考试的5个衔接技巧
冷凝法巧做雅思听力训练
雅思听力备考你不得不知的六条信息
雅思听力高分技巧:克服“语音不全”
如何避开雅思听力考试8大陷阱
雅思听力:高分不是一蹴而就
雅思听力电话场景备考技巧
雅思听力试题特点及解题的突破要点
雅思听力常考的三种场景
剑桥雅思八:听力之华山论剑“雾中看花”
托福转考雅思:听力要适应英音
雅思听力场景词:银行场景
雅思听力高分策略详解
考雅思 学长总结听力三“攻略”
雅思听力考试的5个特点
雅思听力全方位备考指导
雅思听力材料:圣诞树的来历
轻松拿下雅思听力 “给力”五环节
雅思听力考试四步解题流程
掌握正确方法 攻克雅思听力中出现的数字
雅思考试听力那些事儿:练习注意语速语调
应对雅思考试听力生词有妙招
雅思听力三级跳法:帮考生识别答案
如何应对雅思听力陌生词汇
雅思听力备考效率如何提高
雅思听力答案撰写的三个注意事项
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |