A.64kbit/s B.2.048Mbit/s C.155.520Mbit/s D.622.080Mbit/s
A.準(zhǔn)同步數(shù)字系列B.同步數(shù)字系列C.碼分?jǐn)?shù)字復(fù)用系統(tǒng)D.頻分復(fù)用系統(tǒng)
A.同步復(fù)用、按比特間插B.同步復(fù)用、按字節(jié)間插C.異步復(fù)用、按比特間插D.異步復(fù)用、按字節(jié)間插