单项选择题 A technician arrives in Germany and discovers that when their PC is plugged into the outlet, nopower is received. Which of the following actions should the technician take to get the PC tooperate?（）

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?（）