地下排水

例句：

1. 1. The rainwater is being carefully drained from the basement.
   雨水正在从地下室小心地排出。
2. 2. The pipes were clogged and needed to be unclogged.
   管道堵塞了，需要疏通。
3. 3. The sink was filled with dirty water that needed to be flushed out.
   水槽里满是脏水，需要冲洗干净。