A.快速B.方便C.接頭衰耗小D.故障率低
A.850nmB.1310nmC.1490nmD.1550nm
A.下行語(yǔ)音B.下行數(shù)字視頻C.模擬CATVD.下載數(shù)據(jù)請(qǐng)求