rub rail

例句：

1. 1. The train tracks are straight and level.
   火车轨道直且平。
2. 2. Theengineer carefully inspected therails before starting the work.
   工程师在开始工作前仔细检查了轨道。
3. 3. The new rail system will improvetransportation efficiency.
   新的铁路系统将提高运输效率。