slope of river bed

例句：

1. 1. The car is driving down the hill at a steep slope.
   汽车正以陡峭的坡度下山。
2. 2. The river's bed is very steep, making it difficult to navigate.
   河床非常陡峭，使得航行困难。
3. 3. The slope of the mountain was so steep that it looked like a cliff.
   这座山的坡度太陡了，看起来就像一座悬崖。