bottom spring

例句：

1. 1. The car's suspension system uses a bottom spring to improve handling.
   汽车的悬挂系统使用底部弹簧来提高操控性能。
2. 2. The new tire has a built-in bottom spring that reduces vibration.
   新轮胎内置了底部弹簧，减少了振动。
3. 3.The old car had a worn out bottom spring, which made the ride uncomfortable.
   旧车底部弹簧磨损严重，使得乘坐体验不舒服。