如图所示，套在足够长的绝缘粗糙直棒上的带正电小球，其质量为m，带电量为q，小球可

发布时间：2017-06-16 20:13 │ 来源：www.tikuol.com

题型：选择题

问题：

如图所示，套在足够长的绝缘粗糙直棒上的带正电小球，其质量为m，带电量为q，小球可在棒上滑动，现将此棒竖直固定在沿水平方向的且互相垂直的匀强磁场和匀强电场中．设小球电量不变，小球由棒的下端以某一速度上滑的过程中一定有（　　）

A．小球加速度一直减小

B．小球速度先减小，直到最后匀速

C．杆对小球的弹力一直减少

D．小球所受洛伦兹力一直减小

考点：带电粒子在复合场中的运动

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选词填空。根据短文内容，从方框中选择适当的选项完成短文。(有两个选项是多余的)

A. practicing B. quiet C. as D. interested E. but F. could
G. writing H. successful I. hardly J. singers K. often L. so

        Jay Chou was born in Taiwan, China. He grew up with his mother, and he was a   1 and shy kid. He
didn't do very well in schoolwork. So people thought he would never be   2   in life.
        As a small child, Jay was   3   in music. His mother sent him to learn the piano when he was only three
years old. He loved it and kept on   4   when he was in high school, he 5 play the piano quite well. At the same
time, he showed his talent for writing songs.
        Before Jay became a singer he worked 6 a songwriter. For two years, he spent most of his time 7   for
singers. Some of them are very famous, like Coco Lee and Jacky Cheung Jay released (发行) his first album in
2000, and soon he became quite popular.
        Now Jay is one of the most famous   8   in Asia. However, he is still shy and doesn't    9 talk and smile.
He doesn't speak clearly when he sings or talks, 10   he has a lot of fans.
        Most of his fans like him because he never follows others.
1.               2.               3.                4.                5.
6.               7.               8.                9.                10.

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A．党参，沙参，元参
B．人参，丹参，元参
C．人参，沙参，元参
D．沙参，丹参，元参

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f(1+sinx)-3f(1-sinx)=8x+a(x)，
其中a(x)是当x→0时比x高阶的无穷小，且f(x)在x=1处可导．求曲线y=f(x)在点(6，f(6))处的切线方程．

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