平缓的

例句：

1. 1. The road was smooth as glass when it rained.
   雨天时，道路就像玻璃一样平滑。
2. 2. The paint job on the wall is so smooth that you can't tell it's been touched.
   墙上的油漆工作得如此平滑，以至于你无法看出它曾被触摸过。
3. 3.The car's suspension system was smooth and quiet, making for a comfortable ride.
   汽车的悬挂系统平稳且安静，使得乘坐体验舒适。