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问题 解答题

若不等式：kx2-2x+6k＜0（k≠0）

①若不等式解集是{x|x＜-3或x＞-2}，试求k的值；

②若不等式解集是R，求k的取值范围．

答案

①∵不等式kx2-2x+6k＜0的解集是{x|x＜-3或x＞-2}

∴方程kx2-2x+6k=0的两个根为-3，-2

∴

2
k
=-3+（-2）=-5，

∴k=-

2
5

②：①∵不等式kx2-2x+6k＜0的解集是R

∴

k＜0
△=4-24k2＜0

解得k＜-

6
6

阅读理解

阅读理解。

      My parents and I live in a small house in the forest. There are many tall trees and pretty flowers near

our house. We have some flowers in our small garden. I often water them in the morning.

    There are mountains near the forest. There are many animals in the mountains. Sometimes we can see

some lovely deer (鹿) and naughty (淘气的) monkeys in the forest. I often feed (喂养) some birds in the

trees near my house.

    There is a lake near our house, too. The water in it is very clean. We often swim it in summer. And my

father and I like fishing by the lake. The fish from the lake is tasty and fresh.

     Welcome to our house. You'll enjoy the beautiful lake and the forest!

1. My house is in             .

A. the city              

B. the big village              

C. the forest

2. We have some               in our small garden.

A. trees                  

B. flowers     .                

C. forest

3. The water in the lake is very              .

A. sweet                

B. clean                          

C. black

4. I often feed _            near my house.

A. some lovely deer  

B. some birds            

C. some naughty monkeys

5. The fish from the lake is                .

A. tasty and healthy  

B. tasty and fresh            

C. tasty and sweet
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A．黄继光用胸膛堵住敌人的枪口

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C．“党的好干部”焦裕禄奋斗到生命最后一息

D．雷锋被誉为“解放军的好战士”
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