While previously the gap between the continents had allowed a free flow of water, now the isthmus presented a barrier that divided the Atlantic Ocean from the Pacific Ocean.
以前，大陆之间的鸿沟允许水自由流动；而现在地峡形成了一道屏障，把大西洋和太平洋分隔开来。
3
The slush is compacted by an unknown mechanism, and solid, bubble-free ice is formed fromwater high in soluble organic substances.