Answer:
Carbondioxide gas.
Explanation:
Carbondioxide gas is actually cycled in a web of organisms, The plants takes carbondioxide gas for the process of photosynthesis, this plant is eaten by herbivores for energy and carbondioxide is released in the process of respiration. After that, carnivores feed on these herbivores and oxygen is used in the breakdown of food for releasing energy and carbondioxide gas is also released from the body through breathing so the cycle of carbondioxide gas is continue.
