rolling off

例句：

1. 1. The car was rolling down the hill when I saw it.
   当我看到那辆车时，它正沿着山坡滚动。
2. 2. The snow was rolling down the mountainside.
   雪正在山边滚动。
3. 3. The ice was sliding down the river.
   冰正在沿河滑动。