Question

which describes one of oxygens roles in earths atmosphere?
allows fuels to burn
forms clouds that produce rain
is the gas that animals exhale
is used by plants to produce food

Explanation:

Oxygen is a highly reactive gas that supports combustion. When fuels react with oxygen, they burn. Clouds are formed mainly by water vapor. Animals exhale carbon dioxide. Plants use carbon dioxide to produce food (through photosynthesis).

Answer:

allows fuels to burn