Dolphins, air-breathing mammals 海豚是呼吸空气的哺乳动物

14. It is a coming together of ancient bloodlines.
    而是古老血脉的相聚
15. Sharks, living fossils,
    鲨鱼是活化石
16. virtually unchanged for hundreds of millions of years.
    数亿年来几乎没有改变
17. Dolphins, air-breathing mammals
    海豚是呼吸空气的哺乳动物
18. whose ancestors once roamed on land.
    它的祖先曾遍布陆地
19. Whales, bigger than any other animals that have ever lived.
    鲸鱼是史上最大的动物
20. Birds,
    鸟类

来自《我们星球上的生命 第一季 第一集 Life on Our Planet S01E01 生命法则》第 17 行