Upon the return hike, a frozen river had suddenly completely thawed.

在远足回来的路上，一条结冰的河流突然完全解冻。

We had to cross a frozen river in the middle of winter to sneak across the border into China.

我们不得不在严冬涉水穿过冰冷的河流，偷偷越过边境潜入中国。

They moved in procession down the surface of the frozen river, on foot, and dragging their canoes after them on sledges.

在冰冻的河面上他们拖着载有小船的雪橇列队向南步行。

Thin river ice is a significant issue because winter travel is mainly achieved by using the frozen rivers as a transportation route via snow machines or sled dogs.

河面上的冰层十分重要，当地人冬季出行主要就是通过雪车或狗拉雪橇走冰面上的交通路线。

The project will attempt to artificially build "naleds, " a Russian term for super-thick sheets of ice that naturally form when water flows atop a frozen river or lake.

该工程将试图人工建造一个“naleds”。 该词源于俄语，是指流水经过冰冻的河流或湖泊而自然形成的超厚冰层。