单项选择题
A. Windows Firewall settings
B. DHCP settings
C. Disable HomeGroup
D. Wireless on/off switch
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?（）
单项选择题 Which of the following 802.11 standards can operate at both 2.4 GHz and 5.0 GHz?（）