题目

If a man has a good appetite (胃口), it is thought that he is healthy. When we hear a boy saying, I'm a【1】 hungry as a bear. We are quite sure that he is well.It is a good sign to feel hungry in fact. The body rings the bell to tell us that it needs food.If a boy did not eat, he would grow t【2】 and weaker day by day until he was unable even to walk and at last, he would stop living entirely (完全地). That is what happens when people starve (挨饿) to death.You should know the following things about eating.Firstly, you should eat e【3】 leafy vegetables and some fruit every day 多角度认识物质的变化，有助于我们更好地理解化学知识。 （1）微观角度:某化学反应的微观示意图如图 1 所示。回答下列问题： Ⅰ该化学变化中发生根本改变的微粒是______________ (填“原子”或“分子”)。 Ⅱ参加反应的两种物质的分子个数比为_____________ (填最简整数)。 （2）能量变化角度:进行图 2 所示的实验，认识物质变化中的能量变化。 Ⅰ烧杯中加一定量的生石灰会引起白磷燃烧，从燃烧条件分析生石灰的作用是_______________。 Ⅱ下列物质溶于烧杯中的冷水，能引起白磷燃烧的是______________(填字母符号)。 A氯化钠 B硝酸铵 C浓硫酸 D氢氧化钠