多项选择题
A.renews automatically for the lifetime of the product
B.eliminates network problems
C.generate recurring revenue
D.helps customers speed architectural planning and design
E.produces higher margins than product sales along
F.strengthens customer loyalty
多项选择题 You are the network consultant from passguide.com. You have been asked for which two features of optical networks allow data to be transmitted over extremely long distances?（）
多项选择题 Which three are Cisco architectures?（）
多项选择题 What are five of the seven layers that are found in the OSI model?（）