某学生为了测定由两种元素形成的气态化合物X的组成，做了如图所示的实验，把气体X由注射器A缓慢送入装有CuO的B装置，使之完全反应，得到如下结果：
实验前B管及药品的质量为21.32g，实验后为21.16g C管中收集到的物质电解后可得到H2和O2，在D中收集到的是N2。 X中两元素的质量比是14:3。问：
（1）A的化学式是 ，C中收集到的液体质量是 g；
（2）B中在实验中看到的现象是 ；
（3）B中反应的化学方程式是 。
（4）向一充满A的铝制易拉罐中注入足量盐酸，并立即密封罐口，很快可以看到罐体变瘪了；但过一段时间后，瘪了的罐体又重新鼓起。试回答：
①罐体变瘪的原因是___________。
②罐体重新鼓起的原因是___________。
（1）NH3 ；0.18
（2）黑色固体变红色
（3）2NH3+3CuO
3Cu + 3H2O
（4）①氨气被盐酸吸收，罐内压强减小；
②剩余的盐酸继续跟铝反应生成氢气，使罐内压强增大。
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| It has been argued by some that gifted children should be grouped in special classes. The 1 is based on the belief that in regular classes these children are held back in their intellectual (智力的) growth by 2 situations that are designed for the 3 children. There can be little doubt that 4 classes can help the gifted children to graduate earlier and take their place in life sooner. However, to take these 5 out of the regular classes may create serious problems. I observed a number of 6 children who were taken out of a special class and placed in a 7 class. In the special class, they showed little ability to use their own judgment, relying 8 on their teachers' directions. In the regular class, having no worry about keeping up, they began to reflect 9 on many problems, some of which were not on the school program. Many are concerned that gifted children become 10 and lose interest in learning. However, this 11 is more often from parents and teachers than from students, and some of these 12 simply conclude that special classes should be set up for those who are 13 .Some top students do feel bored in class, but why they 14 so goes far beyond the work they have in school. Studies have shown that to be bored is to be anxious. The gifted child who is bored is an 15 child. | ||||
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