质量为1kg的物体在外力的作用下从静止开始做直线运动，其加速度随时间的变化如图所

发布时间：2017-08-07 00:53 │ 来源：www.tikuol.com

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问题：

质量为1kg的物体在外力的作用下从静止开始做直线运动，其加速度随时间的变化如图所示，则

[ ]

A．第1s内质点动能增加量是2J

B．第2s内合外力所做的功是2J

C．第2s末合外力的瞬时功率是3W

D．0~2s内合外力的平均功率是4.5W

考点：动能定理平均功率和瞬时功率的区别

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完形填空。

     Liu Yu, a fifteen-year-old student from Shangdong, is a running star. He is   1   his school running team
and has always wanted to be a professional athlete. However, his parents won't allow him to train as   2   as
he would like to. "Of course we want to see Liu YU achieve his dreams," says Mr. Liu, "and we know   3
he loves running. That's great, and my wife and I have watched him in every one of his races. We have
nothing against running! But we do think that our son needs to be realistic. Now that he is getting older, he
needs to think about what   4   if he doesn't become a professional runner in the end."
     Liu Yu doesn't really agree. "Well, I think I should   5   to make decisions for myself," he says. "My
parents have always taught me the importance of working hard and not just to do   6   I enjoy. I understand
this. But I'm serious about running. Being a professional runner is the only thing I have ever wanted to do."
     Mr. and Mrs. Liu believe that Liu Yu should study hard in the evenings, and so they don't allow him to
practice running   7   school nights. "I know this might seem strict," says Mrs. Liu, "but we think we're
doing the right thing. He has to understand that very   8   people can become professional athletes. It's a
very   9   dream to achieve. We don't allow him to practice every day because we think he needs to spend
time on his homework."
   But Liu Yu still doesn't agree. "I know my parents care about me," he says. "But they are always talking
about what will happen if I don't succeed. But I will succeed! I think I should be allowed to make this
decision for myself. Only then  10  I have a chance of achieving my dream."

( )1. A. in
( )2. A. much
( )3. A. how often
( )4. A. happens
( )5. A. allow
( )6. A. that
( )7. A. at
( )8. A. little
( )9. A. difficult
( )10. A. do

B. on
B. more
B. how long
B. will happen
B. be against
B. what
B. on
B. a few
B. easy
B. will

C. at
C. many
C. how much
C. will take place
C. be allowed
C. which
C. during
C. few
C. exciting
C. /

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《中华人民共和国继承法》规定的第一顺序继承人中不包括：

A．配偶

B．子女

C．父母

D．兄弟

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社区专职工作人员面试由（）组织实施

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2015年我国钟表全行业实现工业总产值约675亿元，同比增长，增速比上年同期提高1.7个百分点。

全行业全年生产手表10.7亿只，同比增长，完成产值约417亿元，同比增长，增速提高1.9个百分点；生产时钟（含钟心）5.2亿只，同比下降，完成产值162亿元，同比下降，降幅扩大1.3个百分点；钟表零配件、定时器及其它计时仪器产值96亿元，同比增长，增速基本保持上年水平。

2015年我国钟表行业规模以上工业企业主营业务收入365.8亿元，同比增长；实现利润23.4亿元，与上年相比下降，而2015年轻工行业主营业务利润率（利润/主营业务收入）的平均水平为。

2015年我国钟表行业海关进出口总额为92.5亿美元，同比增长，完成出口总额为57.7亿美元，同比增长，进口额34.8亿美元。出口总额中加工贸易额占，较上年缩小2个百分点。

2014年我国钟表行业贸易顺差约为多少亿美元？（）

A.27

B.25

C.23

D.18

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结合现代信息技术发展的特点以及行业发展趋势，我们认为，现代物流系统是 ______、______、______和______的物流系统。

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