A.1700-1發(fā)送與1700-1接收可同纜 B.1700-1發(fā)送與接收可同四線組 C.1700-1發(fā)送與1700-1發(fā)送能用同纜 D.1700-1接收與1700-1接收能同四線組
A.2598.6 B.2598.7 C.2601.3 D.2601.4
A.25 B.55 C.60 D.80
A.260 B.200 C.140 D.240