Please talk about the important role of green plants in maintaining the balance of carbon and oxygen in the biosphere.

Green plants constantly carry out photosynthesis, consuming carbon dioxide in the atmosphere, and the generated oxygen enters the atmosphere in the form of gas, which produces more oxygen than the oxygen consumed by breathing, so that the concentration of oxygen and carbon dioxide in the air in the biosphere is in a relatively balanced state, which is called carbon-oxygen balance for short.

Therefore, the answer is: green plants constantly carry out photosynthesis, consuming carbon dioxide in the atmosphere, and the generated oxygen enters the atmosphere in the form of gas, which produces more oxygen than the oxygen consumed by breathing, so that the concentrations of oxygen and carbon dioxide in the air in the biosphere are in a relatively balanced state, which is called carbon-oxygen balance for short.