通讯电缆线径为 0.4，0.5 10对 20对 30对图片

p1Src=//y2.yzimgs.com/uploads/328648/20161128-154445671.jpg?watermark/2/text/5aSp5rSl5biC55S157yG5oC75Y6C56ys5LiA5YiG5Y6C/font/5a6L5L2T/fontsize/400/fill/I0E3QTlBOA==/gravity/SouthEast"

aa