题型:问答题 简答题 The two primary protocols on which the Internet is based are( ).A.FTP FInd TMAPB.TCP and IPC.TCP and SMTPD.TCP and HTTP 查看答案
题型:问答题 简答题 He _______ busy yesterday, or he _______ you with your experiment.A.was; had helpedB.was; would have helpedC.had been; would have helpedD.were; would have helped 查看答案