“套管实验”具有装置简洁便利等优点，结合下面的图示回答有关问题。
(1)欲利用图A比较碳酸氢钠和碳酸钠的热稳定性，并检验分解产物，最好应在大试管内底部加入 ____（填化学式），石灰水变浑浊的烧杯是 ___（填“甲”或“乙”）。
(2)欲利用图B验证铜与浓硝酸的反应产物，该装置除简洁外，你认为最明显的一个优点是___。
(3)用锌粒和稀硫酸用图C仪器制取并收集一试管氢气，锌粒和稀硫酸应放在____（填“大”或 “小”）试管中组成发生装置，理由是____， 该反应的离子方程式为____。
(1) Na2CO3 ；乙
(2)污染物未排入大气，便于控制 反应的进行与停止
(3)小 ；便于收集H2 ；Zn+ 2H+=Zn2++H2↑
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| Like most people, I was brought up to look upon life as a process of getting. It was not until in my late thirties that I made this important 1 : giving-away makes life so much more exciting. You need not worry if you 2 money. his is how I 3 with giving-away. If an idea for improving the window display of a neighborhood store 4 to me, I step in and make the suggestion to the 5 . If an accident takes place, the 6 of which I think the local police could use, I 7 him up and tell him about it, though I am not in 8 here. One discovery I made about this world is to give 9 getting something back, though the 10 often comes in an unexpected form. One Sunday morning the local post office delivered an important special letter to my home, though it was 11 to me at my office. I wrote the postmaster a note of 12 . More than a year later I needed a post-office box for a new business I was 13 . I was told at the window that there were 14 boxes left, and that my name would have to go on a long 15 list. As I was about to 16 the post office, the postmaster appeared in the 17 ."Wasn't it you that wrote us that letter a year ago about delivering an 18 delivery to your home?" I said it was."Well, you certainly are going to have a box in this post office 19 we make one for you. You don't know what a letter like that means to us. We 20 get nothing but complaints." | ||||
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