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问题 单项选择题

为社会提供公证数据的产品质量检验机构，必须经( )以上人民政府计量行政部门对其计量检定、测试的能力和可靠性考核合格。

A．省级

B．市级

C．县级

D．乡(镇)级

答案

参考答案：A

计算题

如图所示，水平地面上方分布着水平向右的匀强电场，场强大小为E0，一个弯成圆周的环状绝缘硬质细管AB竖直固定在匀强电场中。环的半径R=0.30m，离水平面地面的距离为h=5.0m，一带正电的小球从管的上端口A处静止释放，小球大小略小于管的直径，它与管间摩擦不计，小球在电场中受到的电场力大小为重力的一半。（g=10m/s2）求：

（1）小球运动到管口B时的速度大小；

（2）若使带电小球离开环B点瞬间，突然撤去匀强电场，为了使带电小球向右做匀速直线运动，可以加垂直纸面方向的匀强磁场，试求磁场的方向以及磁感应强度大小和原匀强电场强度E的比。

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听力题

缺词填空

根据短文内容和首字母提示，在下文空格处填入适当的词使短文完整。（每空一词）

Welcome to my hometown! Guazhou is my hometown. It is a q 小题1:  town close to the Changjiang River. It has a long history. The air here is so f小题2:  . There are many big supermarkets, beautiful g小题3:   and good factories here. It is very e小题4:   to go shopping. You can see big trees and nice flowers. There are many nice r小题5:   in Guazhou, So you can enjoy Guazhou Fish. It tastes very delicious. Many visitors come here to t小题6:   it. There are many goodp小题7:   to visit. There is a park and a big Shopping Mall. You can see films in Jiangyang T小题8:  . My school is one of theb小题9:   schools in my hometown. It is on Changjiang Road. It is very beautiful. I hope you can come and visit s小题10:  .
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