A.1.1 B.1.468 C.1.66 D.1.723
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