base of the rail

例句：

1. 1. The train's wheels were grinding against the steel rails.
   火车轮子在钢轨上摩擦。
2. 2.The workers had to remove the debris from the base of the rail.
   工人们不得不从铁轨底部清除碎片。
3. 3. The engineer inspected the base of the rail for any signs of damage.
   工程师检查了铁轨底部是否有损坏的迹象。