traction investigation

例句：

1. 1. The car'straction is poor on the wet road.
   这辆车在湿滑的路面上牵引力不足。
2. 2. The weight of the load wastoo much for the tractor'straction.
   负载的重量对拖拉机的牵引力来说太重了。
3. 3. The train's traction system needs to be checked regularly.
   火车的牵引系统需要定期检查。