单项选择题
A.The 4X CD-ROM drive has dirty optics or laser and requires cleaning.
B.The 4X CD-ROM drive needs to be jumpered to support CD-RW disks.
C.The 4X CD-ROM drive does not support the multi-read specification.
D.The 4X CD-ROM is fine， but the CD-RW disk has a flaw in its format.
单项选择题 Ausercomplainsthatacomputermonitorisexperiencingajitter.Replacingthemonitorandvideocarddoesnotfixtheproblem.Whichofthefollowingcouldbecausingtheproblem？（）
单项选择题 AclientasksatechniciantoaddaDVD+Rburnertoacomputersystem.Thetechniciandoesthisandsuccessfullyteststhedrive.Threeweekslater，theclientcallsandsaysthattheburnerisnolongerworking.ThetechnicianlearnsthatthedrivereadsCDsandDVDs，butwillnolongerburnDVDs.Whenarrivingonsite，whatistheFIRSTactionthatthetechnicianshouldtake？（）
单项选择题 Whichcomponentsaredesignedtobeconvenientlyreplacedbyaservicetechnician？（）