单项选择题 A home user working outside an office reports that their laptop is no longer connecting to theInternet. Which of the following would a technician recommend to check FIRST?（）

单项选择题 A technician has a PC that has no Internet connection. The IP address for the PC is 169.254.XXX.XXX. Which of the following should be checked FIRST?（）

单项选择题 A technician installs a new sound card but no sound can be heard. Which of the following utilities can be used to see an error?（）