Why does the sprinkler always sprinkle water before it rains?

It is necessary to keep the road clean in rainy days, but it is inconvenient for sanitation workers to clean it! Not like a sunny day.

Therefore, the relevant departments learned that it was going to rain, so they sprinkled water in advance, in fact, in order to scour the road.

In some places, when it rains, sprinklers also come out to work, all to wash away the garbage and dirt on the road. This is not surprising! !