A.射頻信號(hào) B.視頻信號(hào)和音頻信號(hào) C.中頻信號(hào) D.數(shù)據(jù)信號(hào)
A.SP@ML B.MP@LL C.MP@ML D.HP@HL
A.2 B.4 C.6 D.8