rail/railroad/railway

rail /reil/ n.［c］铁轨，轨道，铁路：Some people were injured when the train went off the rails. 火车出轨时一些人受了伤。He likes travelling by rail.他喜欢坐火车旅行。

 railroad /ˈreilrəud/ n.［c］铁路；铁路系统(BrE. railway)：a railroad bridge铁路桥梁 The railroad slopes up slightly at this point. 铁路从这儿开始微微向上倾斜。My brother is working on the railroad.我兄弟在铁路系统工作。

 railway /ˈreilwei/ n.［c］( AmE. railroad)铁路：an aerial railway高架铁道；railway station 火车站; railway worker 铁路工人；a railway engine机车，火车头；super(high)-speed railway超（高）速铁路 The railways in many countries are owned by the state.许多国家的铁路归国家所有。