A.物理層 B.數(shù)據(jù)鏈路層 C.網(wǎng)絡層 D.應用層
A.255.255.255.0 B.255.255.255.128 C.255.255.255.192 D.255.255.255.224
A.10.110.12.0 B.10.110.0.0 C.10.0.0.0 D.10.110.12.30