单项选择题 A user reports that the wireless network is slow and is able to see and access shared folders that are unknown to the user. Which of the following is the cause of the problem?（）

单项选择题 A second network card in a server that activates if the primary card fails is an example of which of the following network performance optimization?（）

单项选择题 Which of the following cables would a technician make in order to identify a physical interfaceproblem?（）