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
As ocean currents shifted 随着洋流的变化
the continents had shifted almost to where they are today. 各大♥陆♥几乎漂移到了今天所在的位置
They have already shifted sand 它们已经搬运了
The main body of these dunes may not have shifted for 5,000 years. 这些沙丘的主体 可能已有5000多年未曾移动