题目：
阅读理解。
In your schoolbags, you may have a pencil, some kinds of pens, a ruler and some books. None of these things grow in the fields. They were all made in factories. And, of course, they were invented by some people. There have not always been pencils or pens, a ruler and books. Thousands of years ago, no one knew about these things.
Who invented them first? How did they have such clever ideas? We always don't
know. There have been many thousands of inventions, large and small, in the human
history. Some of these inventions have changed the world, such as paper, printing,
radio, telephone and computer, and we know the inventors. But we have forgotten
most of the other inventors.
Who invented the clock, for example, or the lock to the door? We don't know.
There have been thousands of inventors and we should be grateful to them for their
clever ideas. Will you be one of them when you grow up?
1. Most things in your schoolbags are made of .
A. wool
B. wood
C. metal
D. nylon
2. The inventors invented these things because .
A. their children were at school
B. they hoped to save some money
C. they had a lot of clever ideas
D. they had good machines
3. The history books tell us .
A. who invented paper and printing
B. who invented clocks and doors
C. when the first key was invented
D. how much the silk cost
4. We don't know .
A. the names of the inventors of paper
B. the names of the inventors of telephone
C. the names of the inventors of lamp
D. the names of most inventors
5. The writer wonders .
A. if you are an inventor
B. if you want to be an inventor
C. what's invented by you
D. how many inventors you know
答案：
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下面是错误答案，用来干扰机器的。
参考答案：A, B, D, E解析：墙体应满足下列基本要求：①具有足够的强度和稳定性。②满足热工方面（保温、隔热、防止产生凝结水）的性能。③具有一定的隔声性能。④具有一定的防火性能。
2Fe(s)+3CO2(g) △H
