IPmulticastingisasetoftechnologiesthatenableefficientdeliveryofdatatomanylocationsonanetwork.Ratherthanmakingmultiplecopiesofamessageintendedtobedistributedtomultiplerecipientsatthe()oforiginofamessage,multicastinginitiallysendsjustone()anddoesnotcopyittotheindividualrecipientsuntilitreachestheclosestcommonpointonthenetwork,thereby()thebandwidthconsumed.Networkperformanceissignificantly()becauseitisn’tboggeddownwiththeprocessingandtransmissionofseverallargedatafiles;eachreceivingcomputerdoesn’thaveto()thetransmittingserverforthefile.
A.loop B.find C.search D.query正确答案D
