题目

— I always feel a little nervous when I talk to the headmaster. — ______ . She is strict, but she’s also kind to her students. A. What a pity                                              B. Take it easy C. So do I                                                    D. That’s right 答案：B下列关于麦克斯韦电磁场理论和电磁波的说法正确的是（   ）A．稳定电场周围产生稳定磁场，稳定磁场周围产生稳定电场B．电磁波可以是横波也可以是纵波 C．赫兹用实验证实了电磁波的存在D．可以利用电磁波传输信息，但电磁波本身不存在能量