把质量相等的A、B两物体挂在图所示的滑轮组下而，不计绳子、滑轮的重力和摩擦，放手后(    )

​

等量异种点电荷的连线和其中垂线如图所示，现将一个带负电的检验电荷先从图中a点沿直线移到b点，再从b点沿直线移到c点．则检验电荷在此全过程中（   ）

等量异种点电荷的连线和其中垂线如图所示，现将一个带负电的检验电荷先从图中a点沿直线移到b点，再从b点沿直线移到c点．则检验电荷在此全过程中（   ）

  2011年是伟大的中国共产党90华诞。某校九年级(3)班召开了一次题为《沿着光辉的足迹胜利前行》的主题班会，下面是此次主题班会的几个片段。
在“感受辉煌”环节，甲同学列举了我国在发展中国特色社会主义道路上所取得的成就：
①进一步完善立法，对关系到人民身体健康的食品安全问题进行重点检查；
②我国成为全世界吸收外商直接投资最多的国家之一，对外出口不断增加；
③推进文化大繁荣，文化建设投入的力度不断加强，文化事业经费逐年增加；
④积极构建健康合理的消费文化。如政府制定对实木地板征收消费税的政策；

  2011年是伟大的中国共产党90华诞。某校九年级(3)班召开了一次题为《沿着光辉的足迹胜利前行》的主题班会，下面是此次主题班会的几个片段。
在“感受辉煌”环节，甲同学列举了我国在发展中国特色社会主义道路上所取得的成就：
①进一步完善立法，对关系到人民身体健康的食品安全问题进行重点检查；
②我国成为全世界吸收外商直接投资最多的国家之一，对外出口不断增加；
③推进文化大繁荣，文化建设投入的力度不断加强，文化事业经费逐年增加；
④积极构建健康合理的消费文化。如政府制定对实木地板征收消费税的政策；

阅读理解

    Owning a smartphone may not be as smart as you think. It may let you surf the Internet, listen to music and snap photos wherever you are…but it also turns you into a workaholic, it seems.

    A study suggests that, by giving you access to emails at all times, the all-singing, all-dancing mobile phone adds as much as two hours to your working day. Researchers found that Britons work an additional 460 hours a year on average as they are able to respond to emails on their mobiles.

    The study by technology retailer Pixmania reveals the average UK working day is between 9 and 10 hours, but a further two hours is spent responding to or sending work emails, or making work calls. More than 90 percent of office workers have email-enabled phones, with a third accessing them more than 20 times a day. Almost one in ten admits spending up to three hours outside their normal working day checking work emails. Some workers confess(承认) they are on call almost 24 hours a day, with nine out of ten saying they make work emails and calls outside their normal working hours. The average time for first checking emails is between 6 a.m. and 7 a.m., with more than a third checking their first emails in this period, and a quarter checking them between 11 p.m. and midnight.

    Ghadi Hobeika, marketing director of Pixmania, said, “The ability to access literally millions of apps, keep in contact via social networks and take photos and video as well as text and call has made smartphones invaluable for many people. However, there are drawbacks. Many companies expect their employees to be on call 24 hours a day, seven days a week, and smartphones mean that people literally cannot get away from work. The more constantly in contact we become , the more is expected of us in a work capacity(容量).”

如图所示，平行放置的金属板A、B组成一只平行板电容器，保持开关S闭合，若A、B金属板间距增大，电容器所带电荷量Q、电容C、两板间电势差U，电容器两极板间场强E的变化情况是（   ）