单项选择题
A.0.4mΩ B.0.5mΩ C.0.6mΩ D.0.8mΩ
A.0.5~2.5mm B.0.8~2.5mm C.0.8~1.5mm D.0.1~1mm
A.减少同频干扰 B.调整天线的增益 C.增大天线的前后比 D.以上都不对