2. Solid air pollutants called may reduce the energy
available for photosynthesis.
3. If nitrogen and sulfur oxides dissolve in raindrops, the result is
rain.
4. Mercury and lead are examples of pollutants called
5. The pollutants in question 4 enter food chains from the
6. Acid rain has a pH value of less than
7. CFCs are human-made chemicals that contain the element
