1.反刍:牛、羊吃草时,先把草在嘴里粗嚼,然后咽到胃里。休息时再把胃里泡软的草回吐到嘴里重新嚼磨,磨细后再吞到胃里消化。这种吃食的方式叫反刍。2.保护色:有些动物身体外部的颜色跟它们活动的环境颜色很相近,这叫做保护色。这种保护色既可以保护自己不被天敌发现,又为捕食其它动物提供方便,比如青蛙、鳗鱼、蝴蝶、梅花鹿等。3.鸟类适于空中飞行的特点:鸟的翅膀和尾部上的大羽毛是飞行的工具。鸟的身体两头小、中间大、羽毛光滑(羽毛上有油脂),可减少飞行的 1. Rumination: cattle, sheep grazing, first grass in his mouth to chew, and then swallowed into the stomach. Rest and then the stomach soaked soft grass spit into the mouth to chew again, after grinding and then swallowed the stomach digestion. This way of eating is called rumination. 2. Protection color: Some animals outside the body color with the color of their activities is very similar to the environment, which is called the protection of color. This protective color can not only protect themselves from the natural enemies found, but also to facilitate the predation of other animals, such as frogs, eels, butterflies, sika deer and so on. 3. The characteristics of birds suitable for flying in the sky: the big feathers on the wings and tail of a bird are flying tools. Bird's body two small, middle large, smooth feathers (feathers have grease), can reduce the flight