【托福培训-写作】托福写作范文欣赏：Cells and Temperature

新托福考试写作如果考生想拿高分，脑子里一定要有几篇文章，背上几篇范文，能以备不时只需。托福写作是中国考生的弱项，只有在日常生活中多读些范文，了解托福写作中的逻辑思维，才可更好的进行锻炼。下面我们一起欣赏这篇托福写作范文。

　　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.

　　我们并不主张考生死记范文，考试时如果遇到类似题目照搬上去，这并不能考察考生的写作能力。新托福考试写作多背一些范文，可以积累一些素材，像好的短语、词、句等，灵活运用。