天线波束宽度是指方向性图上（）的一半处两个方向上的夹角。
参考答案：功率最大值
Excited to see you back safe and sound from Libya. How long ________ in Libya?[ ]
A. have you stayed
B. did you stay
C. had you stayed
D. would you stay
教学系统设计过程模式
