What is the main cause of brown or photochemical smog?
1. emissions from aircrafts
2. aerosol cans and coolants
3. emissions from automobiles
4. coal-burning industries
5. river pollution through discharge of industrial wastes
1. emissions from aircrafts
2. aerosol cans and coolants
3. emissions from automobiles
4. coal-burning industries
5. river pollution through discharge of industrial wastes
33 answers
10 answers
1 answer
4 answers