True False 4. Rocks Sand Mud Dust is tiny, dry pieces of dirt. Crops are grown on farms. True False 6. Chemicals Rocks Plants Pesticides are chemicals that kill insects.
Filters prevent most bad chemicals from coming out of smokestacks.
True False 8. Fog Haze Snow Smog is air pollution that you can see. Fertilizers help plants grow. True False 10. Smokestacks from Schools Farms Homes Factories can pollute the air.