1.?只(zhi)不過是(shi)，4芯(xin)其(qi)中有兩芯(xin)是(shi)備用。

2.?好象(xiang)是(shi)一(yi)樣的用。

3.?是(shi)有2芯是(shi)備用的啦！沒有什么(me)特別(bie)的區別(bie)。

4.?日常用的(de)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)就(jiu)(jiu)是電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)的(de)進戶線(xian)(xian)(xian)(xian)。常見的(de)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)都(dou)是平行的(de)兩(liang)(liang)路電(dian)(dian)(dian)纜，其材質(zhi)一般為銅、鐵、鋁(lv)，少(shao)數(shu)的(de)關鍵(jian)性線(xian)(xian)(xian)(xian)路會鍍錫、鍍銀。市(shi)場上(shang)所售(shou)的(de)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)有4芯(xin)(xin)(xin)和2芯(xin)(xin)(xin)之分，四(si)(si)芯(xin)(xin)(xin)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)就(jiu)(jiu)是有四(si)(si)根內芯(xin)(xin)(xin)。四(si)(si)芯(xin)(xin)(xin)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)接的(de)時候(hou)只(zhi)需將中間兩(liang)(liang)根線(xian)(xian)(xian)(xian)一樣(yang)顏色(se)就(jiu)(jiu)行，不(bu)用區分極性。但是在電(dian)(dian)(dian)信機房中，因為電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)需要(yao)捆綁寬帶(dai)，所以分為AB線(xian)(xian)(xian)(xian)。正規廠家(jia)生產的(de)四(si)(si)芯(xin)(xin)(xin)電(dian)(dian)(dian)話(hua)(hua)(hua)(hua)線(xian)(xian)(xian)(xian)都(dou)是一根白(bai)一根色(se)線(xian)(xian)(xian)(xian)，那么(me)白(bai)就(jiu)(jiu)為A線(xian)(xian)(xian)(xian),色(se)線(xian)(xian)(xian)(xian)為B線(xian)(xian)(xian)(xian)。