多项选择题
A.Quality of Service （QoS）
B.Intelligent platforms
C.Mobility and scalability
D.Security
E.High availability
多项选择题 WhichQoSmechanismscanyouuseonaconvergednetworktoimproveVoIPquality？（）
单项选择题 YouareanetworkadministratorofalargeinvestorrelationscompanythatusesaswitchednetworktocarrybothdataandIPtelephonyservices.WhyshouldyoucarryvoicetrafficonaseparateVLAN？（）
单项选择题 According to the information presented in the following exhibit， can you tell me the reason that thetrust state of interface FastEthernet 0/3 displays "not trusted"？（）