sewer rat

例句：

1. 1.The sewer rat was a constant source of trouble for the neighborhood.
   下水道老鼠是这个街区不断制造麻烦的源头。
2. 2. The sewer rats were causing a lot of damage to the city's infrastructure.
   下水道老鼠正在给城市的基础设施造成很多损害。
3. 3.The sewer rats were responsible for spreading disease throughout the area.
   下水道老鼠负责在整个地区传播疾病。