The mammals' journey into the oceans was a gradual one. 哺乳动物进入海洋的过程是渐进式的
This is the story of their epic journey... 本集将讲述它们史诗般的征程
The chimps make this dangerous journey every day. 每天 黑猩猩都要经历这样的危险旅行
The journey back to the river will take hours. 回到河流的路途将花费数小时
..freshwater has been making this journey. 淡水便无休止的循环往复
Surely an impossible journey for a fish. 对鱼来说 无疑是一处不可能的目的地
Next time, a journey to Earth's greatest wilderness - 下一集 茫茫荒野之旅