单项选择题
A. Change the BIOS settings to the local time
B. Adjust the voltage selector switch
C. Attach a 220 volt power strip from the current region to the PC
D. Attach a 120 volt battery backup power supply to the PC
单项选择题 The contrast ratio for an LCD monitor is BEST defined as the ratio between:（）
单项选择题 A user can no longer launch their word processing program. The program worked fine yesterday.Which of the following options could BEST be used to fix the word processing program?（）
单项选择题 A user is having problems printing. The technician believes the printer may be out of ink. Which of the following troubleshooting steps should be performed NEXT?（）