电话线直流阻抗_国标电话线直流阻抗

p1Src=//y3.yzimgs.com/uploads/303765/201623-74924423.jpg?watermark/2/text/5aSp6IGU55S157yG572R/font/5a6L5L2T/fontsize/300/fill/I0E3QTlBOA==/gravity/SouthEast"

aa