题目

A man came home from work late, tired and irritated, to find his 5-year-old son waiting for him at the door. “Daddy, may I ask you a question?” “Yeah sure, what is it?” replied the man. “Daddy, how much do you make an hour?” “That’s none of your business. Why do you ask such a thing?” the man said angrily. “I just want to know. Please tell me. How much do you make an hour?” pleaded the little boy. “If you must know, I make $20 an hour.” “Oh,” the little boy replied, with his head down. Looking up, he said, “Daddy, may I please borrow $10?”The father was furiou与吸入的气体相比，呼出气体中总是氧的含量减少，二氧化碳的含量增多，其根本原因在于（ ）A．肺泡内的气体交换B．气体在血液中的运输C．气体在呼吸过程中的扩散D．组织细胞氧化分解有机物消耗氧，产生二氧化碳