单项选择题 Which of the following percentages is required for Disk Defragmenter to fully defragment thevolume?（）

单项选择题 A technician is working on a PC that may have malware. Which of the following should thetechnician try FIRST?（）

单项选择题 Which of the following errors are caused by leaving a floppy disk in the drive when a computer is powered on?（）