向下流

例句：

1. 1.The river flows through the town, providing a source of fresh water for the residents.
   这条河流过这个城镇，为居民提供了水源。
2. 2. The fish swim downstream to spawn in the warmer waters.
   鱼类游向下游产卵。
3. 3.The farmers need to monitor the water quality downstream to ensure the safety of their crops.
   农民需要监测下游的水质以确保作物的安全。