单项选择题
A.Replace the power supply unit.
B.Reseat the systems memory.
C.Reset the proper jumper.
D.Re-install the operating system.
单项选择题 Whichofthefollowingistherecommendedmaintenanceforalaserprinter？（）
单项选择题 Alaserprinterissentforrepairandtheworkorderindicatesthatthereisanimageprintingproblem.WhichofthefollowingshouldatechniciandoFIRSTtoconfirmthisproblem？（）
单项选择题 WhichofthefollowingmaycauseaprintertonotprintcorrectlyafterupdatingfromWindows98toWindowsXP？（）