第一章引言人类的生命,必须靠着食物才能维持。不但人类是这样,凡是一切有生命的东西,无论动物植物以至於微生物,他们的生命也无不依靠从环境里吸取食物才可以维持,生命的特徵是:生长,生存,生育,和活动,这也不过是生物摄取食物所起的一串化学变化而已。靠食物维持生活的,虽然不限於人类,同时, Chapter One Introduction Human life must be sustained by food. Not only human beings, but also all living beings, animals and plants, and even micro-organisms, and their lives can all be maintained by taking food from the environment. The characteristics of life are: growth, survival, birth and activity But it is a series of chemical changes that a biological takes in food. Living on food, though not limited to humans,