rail steel

例句：

1. 1. The railway was built to connect cities across the country.
   这条铁路是为了连接全国各城市而建的。
2. 2. The engineer used a special type of rail steel for the bridge construction.
   工程师使用一种特殊的铁路钢来建造这座桥。
3. 3. The trains were made from high-quality rail steel, ensuring safety and durability.
   火车是由高质量的铁路钢制造的，确保了安全性和耐用性。