traction variable-speed control

例句：

1. 1. The car's engine has a strong traction system.
   汽车的引擎有一个强大的牵引系统。
2. 2. The team needs to improve their traction on the ice.
   团队需要提高他们在冰上的牵引力。
3. 3. The new tire design offers improved traction for better performance.
   新的轮胎设计提供了更好的牵引力，以获得更好的性能。