ring canal

例句：

1. 1. The engineer designed a ring canal to divert the floodwaters.
   工程师设计了一个环形沟渠来转移洪水。
2. 2. The construction of the ring canal was completed ahead of schedule.
   环形沟渠的建设提前完成了。
3. 3. The ring canal is essential for maintaining water quality in the river.
   环形沟渠对于维护河流水质至关重要。