A.數(shù)據(jù)報(bào)和虛電路 B.數(shù)據(jù)報(bào)和存儲(chǔ)轉(zhuǎn)發(fā) C.虛電路和存儲(chǔ)轉(zhuǎn)發(fā)
A.單模 B.雙模 C.多模 D.多模變率