He persuasively argued that such an ice-free corridor did not exist until much later, when the continentalice began its final retreat.
他很有说服力地指出，直到很久以后，当大陆上的冰开始最后消退时，才有了这样一条没有冰的走廊。
2
Evidence that an ice-free corridor between two ice sheets developed when the continentalice first began to melt came primarily from radiocarbon dating.
当大陆上的冰开始融化时，两块冰原之间形成了一条无冰走廊，这一证据主要来自放射性碳测年法。
3
When an ice age begins, the continentalice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it.