单项选择题 A customer reports to Karen, a technician, that he is experiencing problems with the display after his computer is fully booted but reports seeing the BIOS splash screen during boot. Which of the following would MOST likely be the cause?（）

单项选择题 Which of the following command line utilities can Karen, a technician, use to check for open ports?（）

单项选择题 An alternative to plain old telephone service (POTS) would be:（）