Petrochemicals include many things, I would say All of the above. Hope this helped! :)
A vaccine works by stimulating the immune system to produce antibodies without actually infecting someone with that disease. They trigger the immune system to produce its own antibodies as though the body has been infected with the disease. But a vaccine will not make someone immune to a disease, it will simply help the body be able fight the infection better.
Answer:
Ozone
Explanation:
Ozone is considered a pollutant in the troposphere, but in the stratosphere it is essential to life on earth because it absorbs biologically harmful UV radiation. The mesosphere and the thermosphere are two additional atmospheric layers above the stratosphere.