单项选择题 An administrator finds a phone line but does not know where the line goes or if it is active. Whichof the following can be used to test if it is active?（）

单项选择题 Which of the following devices would allow a technician using a packet sniffer to view all the dataon a network?（）

单项选择题 A server keeps rebooting at various times throughout the day. Which of the following tools wouldBEST help to diagnose this issue?（）