third-speed gear

例句：

1. 1. The car has a third-speed gear that allows you to easily switch between low and high gears.
   这辆车有一个第三档速比，可以让你轻松地在低速和高速之间切换。
2. 2.The mechanic adjusted the third-speed gear on the car to improve its performance.
   机械师调整了车上的第三档速比，以提高其性能。
3. 3. During the race, the driver quickly shifted into third-speed gear to gain an advantage over his competitors.
   比赛期间，驾驶员迅速切换到第三档速比，以获得相对于竞争对手的优势。