青蛙的栖息地:river,lake,pond,tree,desert 青蛙的食物: dragonfly, cricket, bug,worm,mouse,other frocs 青蛙的颜色和身上的图案: green,brown,stripe,spot,red,yeliow.orange, bright blue 青蛙的生长阶段: egg,tadpole, frog 形容词性物主代词的用法，例如: your,its,their 疑问代词的用法，例如: what 指示代词的用法，例如: this, that, these 情态动词的用法，例如: can, may 时间状语从句，例如: Some frogs'throats puff up when they make sounds. 特殊疑问句，例如:What is that sound? 祈使句，例如: Look at this frog croaking!