精选优质文档-倾情为你奉上新东方优美背诵短文50篇 Unit50:CellsandTemperature50. Cells and Temperature ?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 impa
