单项选择题 Which Cisco product is a hardware component that supports content filtering and other gateway security functions for the Catalyst 6500 Series?（）

单项选择题 Wide Area Network (WAN) is a computer network that covers a broad areA. Which statement is correct for wide-area network (WAN)?（）

单项选择题 Cisco Technical Support Services portfolio provide customers resources that help ensure that Cisco products operate efficiently, remain highly available, and benefit from up-to-date system software. Is it correct?（）