horseshoe-shaped sewer

例句：

1. 1.The city's sewers are designedto handle the heavy traffic.
   城市的下水道设计用来处理大量的交通流量。
2. 2. Thesewer system is acrucial part of the city's infrastructure.
   下水道系统是城市基础设施的重要组成部分。
3. 3. The sewer was cloggedwith waste and had to be cleaned out.
   下水道被废物堵塞了，需要清理。