Which describes one of oxygen's roles in Earth's atmosphere

Oxygen: Oxygen is one of the essential gases for the living beings to survive. The plants produce oxygen as a result of photosynthesis and it has a wide range of role in Earth's atmosphere. Roles: Allows fuels to burn - Oxygen is the reason for combustion. Hope this helps :))

Explanation:

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )