has been a feature of life on Earth for hundreds of millions of years. 数亿年来 一直是地球生命的特点

303. and silently...
     悄无声息地
304. does it.
     展开行动
305. The rivalry between mammals and reptiles
     哺乳动物与爬行动物的竞争
306. has been a feature of life on Earth for hundreds of millions of years.
     数亿年来 一直是地球生命的特点
307. But their early rise was not to last,
     但它们的早期崛起并不会持续太久
308. because in the far north of Pangaea,
     因为在盘♥古♥大♥陆♥遥远的北方
309. something catastrophic was happening.
     灾难正在发生

来自《我们星球上的生命 第一季 第三集 Life on Our Planet S01E03 入侵大地》第 306 行