上行链路和下行链路之间的频率间隔（双工间隔）为 （）MHz，频率间隔为（）kHz。这样，系统的双工频点数共为（）个.
参考答案：45；200；124
Who's that girl?[ ]
A. She's my mother
B. He's my father
C. She's my sister
— Can you see _________ in the tree?
—No, I can see _________ . [ ]
A. something; nothing
B. anything; nothing
C. nothing; anything
D. anything; something
