Provisions available in local shops have to be flown into Nunavut on one of the most costly air networks in the world, or brought by supply ship during the few ice-free weeks of summer.
He persuasively argued that such an ice-free corridor did not exist until much later, when the continental ice 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。
3
Evidence that an ice-free corridor between two ice sheets developed when the continental ice first began to melt came primarily from radiocarbon dating.