单项选择题
Which type of backup backs up only data blocks modified since the most recent backup at the same level or lower?（）
A.Differential incremental backup B.Different incremental backup C.Cumulative backup D.Cumulative incremental backup
单项选择题 Whichofthefollowingbestdescribesafullbackup?（）
单项选择题 Howisblock-changetrackingenabled?（）
单项选择题 Youhavelostdatafile4fromyourdatabase.Whichistypicallythefastestwaytorestoreyourdatabase?（）
