单项选择题 A user states that email is not being received. Which of the following protocols should thetechnician check for incoming mail?（）

单项选择题 User profiles in Windows 7 are stored in which of the following locations?（）

单项选择题 A user reports that their machine seems to be running slower than usual. The user states that the computer has become progressively worse as more applications are installed. Which of the following is the FIRST step the technician should take?（）