counter-rail

例句：

1. 1.The train's counter-rail is worn smooth from years of use.
   火车的钢轨因多年使用而磨损光滑。
2. 2.The engineer carefully checked the counter-rail before starting the engine.
   工程师在启动引擎前仔细检查了钢轨。
3. 3.The workers were busy replacing the old counter-rail with new ones.
   工人们忙于用新的钢轨替换旧的。