单项选择题
A.voice navigation
B.stylus
C.scroll wheel
D.keyboard
单项选择题 Whichofthefollowingmodesconservesthemostbatterypowerwhileallowingretrievalofthecomputingsessionatalatertime？（）
单项选择题 Ifanexternalmonitorisattachedtoalaptopanditdoesnotwork，whichofthefollowingactionsshouldatechniciantakeFIRST？（）
单项选择题 Afterbootingupanewcomputer，atechnicianobservesthattheUSBportsarenotworkingwithanyUSBdevices.WhichofthefollowingshouldbedoneFIRST？（）