Background Paragraph: One result of air pollution is acid rain. Acid rain is precipitation with a low (acidic) pH. This rain can be very destructive to wildlife. When acid rain falls in forests, freshwater habitats, or soils, it can kill insects and aquatic life. It causes this damage because of its very low pH. Sulfur oxides and nitrogen oxides in the air both cause acid rain to form ( Figure below ). Sulfur oxides are chemicals that are released from coal-fired power plants. Nitrogen oxides are released from motor vehicle exhaust. 
Story: Bill is planning on moving soon. He wants to move to a city that has fresher air and more wildlife to see. His two options that he must choose from are St. Louis and Seattle. Recently, Seattle has installed a new wind farm, and zero emission solar farm to generate power, while St. Louis recently installed a coal fired power plant. Both cities have similar commercial and industrial sectors, and only differ in how they generate power. 
Question: Which city should Bill avoid to satisfy his goals?
St. Louis.