题目

Today companies have branches around the world. More than 11% of the US managers and workers work online either full-time or part-time, and that number is continuing growing. It is believed that it is a waste of time and money to fly around the world for face-to-face meeting. An effective solution to this problem is to use Web meetings.A large group of presentations, training classes and meetings are done online without losing the face-to-face experience. Web meetings are online meetings where an organizer invites attendees(参会人员) to listen to or watch an online presentation by presente取两个相同的验电器A和B，使A带电，B不带电，可以看到A的金属锡箔张开，B的金属锡箔闭合（如图）．用带绝缘柄的金属棒将A和B上的金属球连接起来，则A、B金属箔张角的变化情况是（ ）A．A和B都不变 B．A变小，B张开 C．A变大，B不变 D．A闭合，B张开