A.公平、公開(kāi) B.等價(jià)有償 C.合理補(bǔ)償 D.協(xié)商一致
A.has been designedB.had been designedC.was designedD.would be designed
A.數(shù)據(jù)鏈路層B.物理層C.網(wǎng)絡(luò)層D.傳輸層