top curve

例句：

1. 1. The top curve of the mountain is a popular hiking trail.
   这座山的顶部曲线是一条受欢迎的徒步路线。
2. 2.The engineer used a top curve to adjust the angle of the beam.
   工程师使用顶部曲线来调整梁的角度。
3. 3. The top curve of the road was smoother than the rest.
   这条路的顶部曲线比其他部分更平滑。