Whales are very large mammals and they living in the sea. 鲸鱼是生活在海里的巨大哺乳动物。

　　They breathe air into their lungs. 它们把空气吸入肺里。

　　They feed their babies milk and they have some hair too. 它们给宝宝喂奶，它们也有一些毛发。

　　There are more than 100 kinds of whales in the world. 全世界有100多种鲸鱼。

　　The average size of whales is over 4-5 meters long. 鲸鱼的平均大小超过4-5米。

　　Whales are categorized as endangered species. 鲸鱼被列为濒危物种。

　　This means catching a whale is illegal. 这就意味着捕鲸是非法的。

　　So, people have to protect whales. 所以，人们必须保护好鲸鱼。