单项选择题
A customer wants to know what version of DirectX the current workstation has installed. Which of the following command line tools would the customer use?（）
A. edit B. systeminfo C. gpedit.msc D. dxdiag
单项选择题 Which of the following would BEST optimize a computer that is heavily used? （）
单项选择题 Which of the following BEST describes the purpose of user account control (UAC) in WindowsVista?（）
单项选择题 A Denial of Service (DoS) attack is:（）
