北极熊的栖息地:Arctic 北极熊的身体部位：位:fur,fat,claws,pads,bumps,paws,legs 北极熊的食物:seal,arctic fox, bird egg,plant, berry 文身代词的用法，例如: themselves 疑问代词的用法，例如: who,what 指示代词的用法，例如: this,that, these 副词的用法，例如: easily,quickly 时间状语从句，例如: Polar bears stay with the ice when they can. 定语从句，例如: Walruses are one of the few animals that polarbears are afraid of. There be句型，例如: There is not much food for polar bears on land.