单项选择题
A. Plug in USB keyboard
B. Check for a disable switch
C. Contact the laptop manufacturer
D. Plug in a USB mouse
单项选择题 A user reports that their hard drive has failed and needs to be replaced. Which of the following should the technician do FIRST?（）
单项选择题 A memory type typically used in high end workstations and not generally found in consumer gradePCs is:（）
多项选择题 Modern desktop computer systems require the following to properly dissipate heat（）