C1083 Heterogeneous Group

The sewers had always been the dirtiest and dirtiest place in the entire city.

The fertilizer from the kitchen, excrement from the bathroom, and all sorts of dirty things were all stored in the sewers. It was precisely because of the existence of the underground sewage that the whole city was kept clean and tidy.

If a city's sewer system was not developed, then the city wouldn't be as clean