rail fastening

例句：

1. 1. The train was traveling on the main railway line.
   火车正在主要铁路线上行驶。
2. 2. The engineer had to repair the damaged rails.
   工程师不得不修理损坏的轨道。
3. 3. The train's wheels were grinding against the rails.
   火车轮子在铁轨上磨擦。