triple-change gear

例句：

1. 1. The car has a triple-change gear system that allows for easy shifting between different speeds.
   这辆车有一个三档变速系统，可以轻松地在不同的速度之间切换。
2. 2. The mechanics at the garage have to change the triple-change gear every time they service the car.
   车库里的技工每次服务汽车时都必须更换三档变速齿轮。
3. 3.During the race, the driver had to quickly change from one gear to another to maintain maximum speed.
   比赛中，驾驶员必须迅速从一种齿轮换到另一种以保持最大速度。