单项选择题
A. Install a new operating system
B. Delete users’ data before donation
C. Write the drive with 1’s and 0’s three times
D. Delete all partitions of the hard drive
单项选择题 A user is trying to connect a mobile IR printer to a mobile device with no success. Which of the following is the MOST important when printing to an IR printer?（）
单项选择题 The network printer is locking up and printing garbled text. When the user cancels the job fromtheir local print queue, nothing happens. Which of the following is the MOST likely cause?（）
单项选择题 Which of the following ISP types requires an RJ-11 connection to the PC?（）