单项选择题
A. The memory is failing.
B. The CPU is overheating.
C. The hard drive is not attached properly.
D. The operating system is not installed.
单项选择题 Which of the following is the default location for user account files in Windows Vista?（）
单项选择题 A client reports that the cursor on their laptop moves to one corner of the screen and stays there when they try to use the keyboard joystick. Which of the following components will MOST likely need to be replaced to resolve the issue?（）
单项选择题 Which of the following is the proper order for powering off and on network components?（）