positive speed gearbox

例句：

1. 1. The new car hasa positive speed gearbox that makes iteasy to accelerate.
   这款新车配备了正速齿轮箱，使得加速变得轻而易举。
2. 2. The engineerreplaced the old gearbox with a moreefficient positive speed gearbox.
   工程师用一个更高效的正速齿轮箱替换了旧的齿轮箱。
3. 3. The vehicle's performancewas greatly improved by the addition of apositive speed gearbox.
   通过增加一个正速齿轮箱，车辆的性能得到了显著提升。