单项选择题 Which of the following commands should Jill, a technician, use to test a computer’s NIC forfunctionality?（）

多项选择题 Which of the following are good examples of malware prevention in Windows XP?（） (Select TWO)

单项选择题 A user reports that a newly installed external CD-RW is not working. Jill, a technician, is called and notes the user has the CD-RW drive, a flash disk, a rarely used external hard drive and a wireless network adapter plugged into an external USB hub. Which of the following is the MOST likely reason for the problem?（）