You are right. People inhale oxygen and exhale the carbon dioxide needed by the plants. In fact, there is no waste of such things. You bring happiness to others every day. This is a kind of value for living.
你说的很对，人们吸入氧气，呼出植物所需的二氧化碳。其实不存在浪费这种事啊，你每天给别人带来快乐，这也是活着的一种价值啊。