A.5μs B.10μs C.5ms D.10ms
A.清0 B.保持當(dāng)前值 C.置1 D.置反
A.物理層是數(shù)據(jù)位 B.數(shù)據(jù)鏈路層是數(shù)據(jù)段 C.網(wǎng)絡(luò)層是數(shù)據(jù)幀 D.傳輸層是數(shù)據(jù)包