单项选择题
A user reports that after configuring the BIOS to boot to the hard drive first, the system still tries to boot from the optical drive. Which of the following is the MOST likely cause?（）
A. Optical drive B. Power supply C. CMOS battery D. CD-ROM disk
单项选择题 Which of the following wireless standards uses the 5GHz frequency?（）
单项选择题 Which of the following will cause a ghost image on a printout?（）
单项选择题 Which of the following commands would a technician use to view the active applicationconnections on a local PC to the network?（）
