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问题 问答题

按要求写出下列反应的化学方程式．

（1）有使带火星木条复燃的气体生成的反应______；

（2）有铜生成的置换反应______；

（3）有红褐色沉淀生成的反应______；

（4）用含氢氧化铝的药片中和过多的胃酸______．

答案

（1）氧气可以支持燃烧，能使带火星的木条复燃，高锰酸钾、氯酸钾、过氧化氢溶液分解都能够产生氧气；

（2）氢气和氧化铜反应可以生成铜单质，故可以写出该反应的化学方程式；

（3）氢氧化钠溶液可以和氯化铁反应生成红褐色的氢氧化铁沉淀，故可以写出该反应的化学方程式；

（4）胃酸中的盐酸可以和氢氧化铝反应生成氯化铝和水，达到中和胃酸的目的，故可以写出该反应的化学方程式．

故答案为：（1）2KMnO4

  △  
.
 
K2MnO4+MnO2+O2↑或2KClO3
MnO2
.
△
2KCl+3O2↑或2H2O2
 MnO2 
.
 
2H2O+O2↑；

（2）H2+CuO

  △  
.
 
Cu+H2O（碳单质也可以其它合理答案亦可）；

（3）FeCl3+3NaOH═Fe（OH）3↓+3NaCl（可溶性铁盐和可溶性碱都可以）；

（4）Al（OH）3+3HCl═AlCl3+3H2O．

阅读理解

A sign can be found in the front yard of a house in the US. The people living here want to let their dog play outside and ensure it won’t run into the street. So, they hire a company to set up an “invisible fence”, an electric wire buried in the ground around the yard. The dog wears a special collar and when it walks near to the “fence”, the wire will send out a small shock. The dog quickly learns to stay away from the edge of the yard. As it says at the bottom of the sign, the fence will keep your dog “safe” (away from the street) and “at home” (contained inside the yard).

The small word “BRAND” printed in blue means that “Invisible Fence” is registered as the company’s brand name. Similarly, the “TM” printed after “your dog safe at home” stands for “trade mark”, a slogan registered specifically to one company.

小题1: The people set up an “invisible fence” _________.

A．to let their dog play outside their house

B．to keep their dog away from the edge of the yard

C．to keep their dog inside their yard

D．to warn others not to enter their house小题2: Which is NOT true about the “invisible fence”?

A．The fence does not exist at all.

B．The “Invisible Fence” is the name of a company.

C．Without the special collar, the fence won’t work on the dog.

D．Science and technology play an important part in it.小题3:
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多项选择题

在自动控制系统中，定值系统是把给定值X（S）固定不变，把干扰作为系统的输入量，那么项目叙述正确的是（）。

A、系统只考虑偏差变量E（S）对干扰量F（S）的响应

B、系统只考虑输出变量Y（S）对干扰量F（S）的响应

C、系统只考虑干扰量F（S）对于偏差变量E（S）影响

D、系统只考虑干扰量F（S）对于被控变量Y（S）影响
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