给煤机胶带为特制的（），具有较好的物理化学性能及较高的几何精度。

只有颅内病变才会引起头痛。()

阅读理解。

     If you do not use your arm or your legs for some time, they become weak, when you start using

them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to

know that memory works in the same way. When someone says that he has a good memory (记忆力),

he really means that he keeps his memory in practice by using it. When someone else says that his

memory is poor, he really means that he does not give it enough chance to become strong. If a friend

says that his arms and legs are weak, we know that it is his own fault. But if he tells us that he has a poor

memory, many of us think that his parents are to blame (受责备), and few of us know that it is just his

own fault. Have you ever found that some people can't read or write, but usually they have better

memories? This is because they cannot read or write and they have to remember things they can write

down in a little notebook. They have to remember days, names, songs and stories, so their memory is

the whole time being exercised.

     So if you want to have a good memory, learn from the people: Practice remembering.

1. The main reason for one with poor memory is that _____. [ ]

A. his father or mother may have a poor memory

B. he does not use his arms or legs for some time

C. his memory is not often used

D. he can't read or write

2. If you do not use your arms or legs for some time, _____. [ ]

A. you can't use them any more

B. they will become stronger

C. they become weak and won't become strong until you use them again

D. they will not change

3. Which of the following is NOT true? [ ]

A. Your memory works in the same way as your arms or legs.

B. Your memory, like your arms or legs,

    becomes weak if you don't give it enough chance for practice.

C. Don't learn how to read and write if you want to have a better memory.

D. A good memory comes from more practice.

4. Some people can't read or write, but they usually have better memories, because _____.  [ ]

A. they have saved much trouble

B. they have saved much time to remember things

C. they have to use their memories all the time

D. they can't write everything in a little notebook

5. Give a best title for this passage _____. [ ]

A. Don't stop using Your Arms or Legs

B. How To Have a Good Memory

C. Strong Arms and Good Memories

D. Learn from the people

电梯如出现显示板无显示的原因有（）、（）、（）。

6时=______分；5分=______秒；134秒=______分______秒．

价格是商品价值的货币表现，而价值则是生产商品所花费的劳动量。 ( )