metrocele

例句：

1. 1. The metro line is a popular tourist attraction in the city.
   地铁线路是这个城市的一个受欢迎的旅游景点。
2. 2.The subway is running smoothly despite the heavy rain.
   尽管大雨，地铁运行得仍然很顺畅。
3. 3.The subway tunnel was completed just in time for the new year's celebrations.
   地铁隧道在新年庆典前刚好完成。