mole drainage

例句：

1. 1. The construction crewis working on the underground mound tocreate a new drainage system.
   施工队正在地下挖掘，以创建一个新的排水系统。
2. 2.The rainwater from the roof has beendiverted into the main drainage pipe.
   屋顶的雨水已被引导到主排水管中。
3. 3. The engineer designed the drainage systemto prevent flooding during heavy rainfall.
   工程师设计了排水系统，以防止大雨期间发生洪水。