"Early to bed, early to rise makes people healthy, wealthy(富有的)and wise(聪明的). "

    This is an old English saying. Children should have ten hours' sleep every night, or they can't do their work very well. They will not be wise, either. The body needs exercise. Walkin9, running, swim-ruing and playing ball games are all exercise. Exercise keeps the body strong and makes the mind bright.

人的生活离不开营养物质和氧气，同时还需要排出体内产生的代谢废物．人体是一个统一的整体，各个系统之间存在着密切的联系．下图是人体进行消化吸收、呼吸、循环、排泄等生理活动的部分结构示意图，请据图回答下列问题（ 中填标号，_____上填文字）：