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问题 选择题
若a，b，c∈R，且a＞b，则下列不等式一定成立的是（　　）
A．a+c≥b-cB．ac＞bcC．
c2
a-b
＞0		D．（a-b）c2≥0
答案

A不正确，由于c的正负未定，若其小于0，则不一定正确；

B不正确，若c为负，或为0，则不成立；

C选项不正确，若c为0，则不等式不成立；

D选项正确，由于a-b＞0，c2≥0，故一定有（a-b）c2≥0

故选D

填空题

根据下列句子及所给的汉语注释，写出空缺处各单词的正确形式。每空只写一词。

1. Supermarkets can't offer plastic shopping __________ (袋) to the customers for free now.

2. Sleep is __________ (必要的) to health

3. I am pleased that he gladly __________ (接受) our invitation.

4. I changed into my sports shoes so that I could walk more __________ (舒服地).

5. The patient kept __________ (咳嗽) all night.

6. During the Spring Festival, a heavy __________ (暴风雪) hit many areas across southern China.

7. Many people gathered at Tai Miao to __________ (庆祝) the 100-day countdown (倒计时) to the

    Beijing Olympic Games on the evening of April 30.

8. She has been a very __________ (勇敢的) little girl.

9. The book should be returned no __________ (迟) than next Friday.

10. Traditional Beijing opera will be __________ (增加) to the music courses in 200 schools in China.

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多项选择题

传染病责任报告人（）

A、公民

B、医务人员

C、社区及乡村医生

D、个体开业医生
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