true tractive force

例句：

1. 1.The true tractive force of a car is determined by its engine size and weight.
   汽车的真实牵引力由其发动机大小和重量决定。
2. 2.The true tractive force of the earth's gravity is incredibly strong.
   地球的重力的真实牵引力非常强大。
3. 3.The true tractive force of a rope is measured in pounds per square inch.
   绳索的真实牵引力以磅每平方英寸为单位测量。