A.UNI B.Q3 C.V5 D.Um
A.數(shù)字?jǐn)?shù)據(jù)在數(shù)字信道上B.數(shù)字?jǐn)?shù)據(jù)在模擬信道上C.模擬數(shù)據(jù)在數(shù)字信道上D.模擬數(shù)據(jù)在模擬信道上