n.冰河作用；凍結(jié)成冰

These hills were formed by glaciation. 這些山丘是冰川作用形成的。

The Great Lakes basins were excavated by the ice, and many present landforms are the result of this continental glaciation. 五大湖盆地都是冰挖掘出來的，如今許多現(xiàn)有地形都是這種大陸冰川作用的結(jié)果。

Pleistocene glaciation caused the extinction of many species. 第四紀冰期，使許多物種絕滅。

n.冰消作用(減冰川作用)