The river bank steepens and we turn up it, away from the river.

河岸变陡了， 我们转身离开河流。

But the slopes rapidly steepened and at length fell away in sheer precipices, compelling a return to the ice.

但是斜坡迅速变陡， 最后在陡峭的悬崖上消失， 迫使人们返回冰面。