单项选择题
A.Providing technical customer support
B.Changing configurations
C.Updating software
D.Monitoring network performance
E.Replacing hardware
F.Scheduling backups
单项选择题 Whichofthefollowingcorrectlyfillsinthemissingwordsofthissentence：AnARPrequestusesaaddress，whereasanARPreplyusesaaddress.（）
单项选择题 WhichofthefollowingeventswouldnotexplainexcessiveCPUutilization？（）
多项选择题 WhichofthefollowingstatementsaretrueforroutersbutnottrueforLayer3Ethernetswitches？（Chooseallthatapply.）（）