What are whales?
Whales are the largest animals of the sea.They are marine mammals that heavily depend on water.Out of water,whales can't live any longer.In order to adapt their life to the water and reduce resistance,their hind limbs disappeared,and their fore limbs gradually changed into oar board.Their bodies are fusiform,resembling the streamlined form of a fish.
鲸是生长在海洋中最大的动物，是对水依赖程度很大的哺乳动物，鲸一旦离开了水便无法生活。为了适应水中生活，减少阻力，它们的后肢消失，前肢变成划水的浆板，身体成为流线型，形体酷似鱼。
鲸鱼
