regulon

例句：

1. 1.The train is running on the main track.
   火车正在主要轨道上运行。
2. 2. The new railway line will connect two cities.
   新的铁路线将连接两个城市。
3. 3. The train's regulon was damaged in the accident.
   火车的轨道在事故中受损了。