but it was only a matter of time. 但这只是时间问题

296. Safe
     安全了
297. and able to breathe once more.
     又能呼吸了
298. Mammals had a long way to go to become masters of the world's oceans,
     哺乳动物想要成为海洋的主宰 还有很长的路要走
299. but it was only a matter of time.
     但这只是时间问题
300. As the planet continued to cool,
     随着地球持续降温
301. it fed an explosion of life...
     生命爆♥炸♥式发展
302. allowing the giants of today to evolve.
     使如今的巨兽得以进化

来自《我们星球上的生命 第一季 第七集 Life on Our Planet S01E07 地球继承者》第 299 行