A: Hey, John's birthday dinner is next week. Let's ____ about the food.

B: Sure. How ____burger, vegetable salad, and some fruit?

C:____ good. John likes hamburgers.

A: Oh, I ____ like salad.

C: But John likes salad, and it's his birthday.

A: Yes, you're right. What about the fruit?

B: I think John likes strawberries and apples.

C: OK. Let's have ____ and apples then.

    I did something wrong today.

    While at the beach this afternoon. I met a boy called Bob We talked a lot. He said that it was fun playing on the cliffs (悬崖). I told him that I was not allowed to go near that place(Mum and Dad had always told me it was dangerous to play there). He called me a coward. I wanted to prove to him that I was just as brave, so I agreed to go with him.

    We wanted to make our way down to explore (探索)the area, so Bob started to climb down and I followed him. Unluckily, some rocks came down after us. One of them nearly hit my head. We could not get back up. We shouted and shouted for help, but for a long time no help came. I was really scared. I wanted to cry. Then, we heard some sounds. Someone had heard us. A woman tied (系 )a rope around herself while a man at the cliff top held the rope. She made her way down to save us.

    My parents were relieved (宽慰的)that I was unhurt, but they were angry that I had done such a risky thing. I apologized and promised that I would not do anything like that again.

（1）在NaNO₃中N的化合价是　 ____　价；在NH₄Cl中N的化合价是 ____　价．

（2）请根据物质的“俗称”写出相应的化学式

大理石　 ____　、纯碱　 ____　、烧碱　 ____　、铜绿　 ____　、胆矾　 ____　、

（3）请根据物质名称写出相应的化学式

硝酸　 ____　、碳酸氢钙　 ____　、高锰酸钾　 ____　、硫酸钡　 ____　、硫酸铝　 ____　、

（4）A、B、C、D四个试剂瓶中分别盛碳酸钠、硝酸银、烧碱、稀硫酸四种稀溶液中的一种，取四种溶液各少量，依次滴入物质X的溶液和稀硝酸，发生的现象如表所示：

回答：

①物质X的化学式是　 ____　．

②物质B是 ____，加入X后反应的化学方程式是　 ____　，加稀硝酸后，沉淀消失的反应化学方程式是　 ____　．

③为进一步区别A和C，可根据置换反应的原理进行实验，写出其中一个反应的化学方程式 ____