单项选择题 A system administrator installed a new switch using a script to configure it. IP connectivity was tested using pings to SwitchB. Later attempts to access NewSwitch using Telnet from SwitchA failed. Which statement is true?（）

单项选择题 A host is attempting to send data to another host on a different network. What is the first action that the sending host will take?（）

单项选择题 When two hosts are trying to communicate across a network, how does the host originating the communication determine the hardware address of the host that it wants to "talk" to?（）