单项选择题
A.255.255.255.0
B.255.255.255.240
C.255.255.255.248
D.255.255.255.252
E.255.255.255.254
单项选择题 Whichroutingprotocolbydefaultusesbandwidthanddelayasmetrics?（）
多项选择题 AcompanyisinstallingIPphones.Thephonesandofficecomputersconnecttothesamedevice.Toensuremaximumthroughputforthephonedata,thecompanyneedstomakesurethatthephonetrafficisonadifferentnetworkfromthatoftheofficecomputerdatatraffic.Whatisthebestnetworkdevicetowhichtodirectlyconnectthephonesandcomputers,andwhattechnologyshouldbeimplementedonthisdevice?(Choosetwo.)（）
单项选择题 Anetworkinterfaceporthascollisiondetectionandcarriersensingenabledonasharedtwistedpairnetwork.Fromthisstatement,whatisknownaboutthenetworkinterfaceport?（）