单项选择题
A.alerts
B.errors
C.critical
D.notifications
问答题 YouhavetwoNTPservers10.1.1.1&10.1.1.2andwanttoconfigurearoutertouse10.1.1.2asitsNTPserverbeforefallingbackto10.1.1.1.Whichcommandwillyouuse？
单项选择题 The following commands are issued on a Cisco router： What would be the output shown on the console？（）
多项选择题 WhichtwoofthefollowingoptionsarecategoriesofNetworkMaintenancetasks？（）
