题目

下列说法正确的是（ ） A . 偏振光可以是横波，也可以是纵波 B . 光学镜头上的增透膜利用了光的干涉现象 C . 在LC振荡电路中，当电流最小时，线圈两端电势差最小 D . 声源与观察者相对靠近时，观察者所接收的频率大于声源振动的频率 答案：B,D选择合适的答句 A. When is your birthday?B. Yes, I do. C. I often sing birthday song. D. Which season do you like best?E. Why do you like winter best?A. When is your birthday?B. Yes, I do. C. I often sing birthday song. D. Which season do you like best?E. Why do you like winter best?Amy: Hi, Mike. 1.________Mike: Winter.Amy: 2. ________Mike: Because my birthday is in winter.Amy:3. ________Mike: It is in January.Amy: What do you often do on your birthday?Mike:4. ________ Do you like winter?Amy:5. ________ I like winter, too. Because I can play in the snow.