单项选择题
A printer is not pulling paper out of the paper tray. Which of the following is the MOST possible cause of the problem? （）
A. Pickup rollers B. Print head C. Drum D. Fuser
单项选择题 Which of the following expansion cards can be installed into an AGP slot?（）
单项选择题 Which of the following offers the HIGHEST wireless security?（）
单项选择题 Which of the following network media types uses laser light to carry the information?（）
