Answer: Because They fall back to earth in the form of rain, sleet, hail, snow and dust. Most acid rain is caused by humans in the form of burning of fossil fuels. A very small percentage of acid rain is caused by natural causes such as volcanoes or wildfires.Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere. ... In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air.
Step-by-step explanation: