A.2~4 B.4~6 C.6~8 D.4~8
A.傳輸?shù)墓β蕦?、通信容量?br /> B.傳輸損耗大 C.不受電磁干擾 D.質(zhì)量輕
A.VPWS、流、tunnel B.流、VPWS、tunnel C.tunnel、VPWS、流 D.tunnel、流、VPWS