circulating water channel

例句：

1. 1. The hospital has a circulating water channel that helps to keep the air fresh in the operating room.
   医院有一个循环水道，有助于保持手术室的空气清新。
2. 2.The engineer designed a circulating water channel to improve the efficiency of the cooling system.
   工程师设计了一个循环水道，以提高冷却系统的效率。
3. 3. The construction workers were working on a circulating water channel project in the basement.
   建筑工人正在地下室进行一个循环水道项目。