Ozone would be the secondary pollutant because it is caused when two primary pollutants react. Hope this helps!
You do have an wonderful theory, but what if they already found the cure for cancer cells? but wont tell us because the government wants us to believe there isnt none so that they can either use it on themselves or wait for the future atleast a million people die from cancer everyday but how come they havent "supposedly" found a cure yet?
When exercising is when the lungs work the hardest because you're using a lot of muscles and are running around and are using force in your body so the lung works really hard to make sure the body gets enough air while working out.
Answer:
D. friction between two rock surfaces grinding away minerals. :)
Explanation:
