It is an indicator of poor air quality from air pollution. This pollution is most often ozone or particulates. Typically it indicates that the air is unhealthy for children, the elderly, and sensitive groups.
18. your last option is the correct answer
I think release of chlorofluorocarbons (cfcs) is most closely associated with sunburns. CFCs are green house chemicals that are more potent than the current greenhouse chemicals such as carbon dioxide and methane,and therefore should not be released to the atmosphere. CFCs release free chlorine which is responsible for destabilizing and destroying the ozone layer, which absorbs most of the UV radiations.
Answer:
it's c
Explanation:
Producers like grass use the sun's energy to stay alive and things like bunnies eat them and so on and so forth.