A.50欧姆B.0欧姆C.20兆欧D.75欧姆
A.64mS 亮\800mS 灭B.64mS 亮\3000mS 灭C.64mS 亮\300mS 灭D.64mS 亮\1000mS 灭
A.混频B.调制C.辐射D.叠加