单项选择题
A client asks a technician to add a DVD+R burner to a computer system. The technician does this and successfully tests the drive. Three weeks later， the client calls and says that the burner is no longer working. The technician learns that the drive reads CDs and DVDs， but will no longer burn DVDs. When arriving on site， what is the FIRST action that the technician should take？（）
A.check for a faulty IDE cable B.be sure that the DVD+R is formatted before using it C.check for incompatible media D.re-install the DVD burning software
单项选择题 Whichcomponentsaredesignedtobeconvenientlyreplacedbyaservicetechnician？（）
单项选择题 Whichtestchecksthetransmitterandreceiverofalocalmodem？（）
单项选择题 Acomputerbootsupwiththeerror"CMOSChecksumFailure."Whichofthefollowingcomponentsneedstobereplaced？（）
