单项选择题 A user has just moved a PC from one office to another. The patch cable and the NIC do notappear to be functioning in the new office but were working before the move. The patch cable is plugged in correctly to both the NIC and the wall jack. Which of the following actions should the technician take FIRST?（）

单项选择题 Which of the following default ports must be opened to allow a technician to telnet into a machine?（）

单项选择题 After opening up the lid of a laptop that is powered on, nothing is displayed on the LCD. Opening and closing the lid multiple times usually causes the display to regain the signal. Which of the following components should the technician check FIRST?（）