Answer;
Responsiveness
Excretion
Explanation;
Excess carbon dioxide must be removed from the body to stop it reaching toxic levels. As the blood flows through the lungs, excess carbon dioxide passes out of the blood and into the alveoli by diffusion. It is then removed from the lungs when we exhale (breathe out).
-Carbon dioxide helps remove carbon dioxide (a waste gas that can be toxic) from your body. The lungs' intake of oxygen and removal of carbon dioxide is called gas exchange. Gas exchange is part of breathing.