人類吸入左氧氣會呼出二氧化碳係因為呼吸作用.
呼吸作用係一種複雜過程含有好多化學作用.呼吸作用係每一個細胞杜進行.
食物在身體燃燒,,從而釋放能量,,二氧化碳同水都一樣釋放左.
"Respiration is a complex process involving many chemical reactions. It occurs in every body cell. During respiration, food is broken down in the presence of oxygen to release energy. The energy released is used to support our body activities. C02 and water are also produced."
呼吸作用:
食物+氧氣---->二氣化碳+水+能量
不可能有 三氧化碳
http://hk.knowledge.yahoo.com/question/?qid=7006050700501