The ice began to melt as Earth's orbit shifted once more 随着地球轨道再次发生变化 冰开始融化
the tundra-steppe became Earth's most extensive habitat. 冻原成为地球上最广阔的栖息地
changes in the Earth's orbit, ocean currents, and carbon dioxide levels 地球轨道、洋流 和二氧化碳水平的变化
had left many of Earth's great habitats free for the taking. 使地球上许多重要的栖息地 变得唾手可得
The asteroid had wiped out three-quarters of all Earth's plant and animal species. 小行星 令地球上四分之三的动植物物种灭绝
and Earth's shifting tectonic plates continued to reshape the planet. 地球板块漂移继续重塑地球
that, for the very first time in Earth's history, 以至于陆地上的物种数量超过海洋
creating the largest delta in Earth's history. 创造出地球历史上最大的三角洲
the Earth's continents had been converging, 地球的大♥陆♥一直在汇聚
Lying dormant for years on end, the colossal forces at work beneath Earth's surface 埋在地球表面之下多年的巨大力量