slope circle

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 slope of the mountain is changing with the weather.
   随着天气的变化，山的坡度在变化。
3. 3. The slope circle was used to measure the angle of the slope.
   坡度圈被用来测量坡角。