单项选择题
A laser printer prints pages with a gray background. Which of the following is the MOST possible cause of the problem? （）
A.Transfer roller B.Paper type C.Print head D.Fuser
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? （）
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?（）
