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问题 选择题
下列方程中，不是一元二次方程的是（　　）
A．
3
y2+2y+1=0		B．
1
2
x2=1-3x
C．
1
10
a2-
1
6
a+
2
3
=0		D．x2+x-3=x2
答案

A、符合ax2+bx+c=0（且a≠0），是一元二次方程，故本选项错误；

B、化简后为

1
2
x2+3x-1=0，符合ax2+bx+c=0（且a≠0），是一元二次方程，故本选项错误；

C、符合ax2+bx+c=0（且a≠0），是一元二次方程，故本选项错误；

D、x2+x-3=x2化简后为x-3=0，是一元一次方程，故本选项正确．

故选D．

填空题

根据下列短文内容，在短文后的空格处填上一个恰当的词，使短文完整、通顺。

    Everyone may fail or may meet with difficulties. When a person meets difficulties, he should adopt(采取)a right attitude(态度)to them. In fact, some people will 1. g_____ up after they fail once. They regard

themselves as failures(失败者),and are not 2. a_____to get over the difficulties.They face up to the failure. They try to find out what the 3. p_____ was. At last, they get over their difficulties. They have the right

attitude to deal with difficulties.

     "Do not ever lose heart." This is the advice given by a successful young man. This young man once got

hurt in his leg. He could never stand as 4. b_____. This was an unlucky thing. But he didn't lose heart. At

last he found out that he could do many things as well as 5. h_____ people. He started to do research on

computers. 6. F_____ he succeeded in becoming an expert(专家)on computers.

     The story tells us not to lose heart whatever 7. h_____ .Difficulties are nothing if you have courage and

confidence in yourself.Let's learn something from the story.Keep on going,and you will make it.Remember: Nothing is 8. i_____ if you put your heart into it!

1. _______2. _______3. _______4. _______5. _______

6. _______7. _______8. _______
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单项选择题

以（）为水源的给水系统，因水质良好，一般可省去水处理构筑物而只需加氯消毒，使给水系统大为简化。

A.地表水

B.地下水

C.浅层地下水

D.海水
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