单项选择题
A.IR
B.DSSS
C.FHSS
D.DSSS and FHSS
E.IR, FHSS, and DSSS
多项选择题 Whataretwosecurityappliancesthatcanbeinstalledinanetwork?(Choosetwo.)（）
多项选择题 Whataretworecommendedwaysofprotectingnetworkdeviceconfigurationfilesfromoutsidenetworksecuritythreats?(Choosetwo.)（）
单项选择题 Forsecurityreasons,thenetworkadministratorneedstopreventpingsintothecorporatenetworksfromhostsoutsidetheinternetwork.Whichprotocolshouldbeblockedwithaccesscontrollists？（）