多项选择题 You are working on an Oracle Database 10g database. Because of data loss， you decided to perform a Flashback Database operation using the following command：  SQL> FLASHBACK DATABASE TO TIMESTAMP（SYSDATE 5/24）  Which two statements are true？ （）

单项选择题 OnTuesday，ajuniorDBAdroppedanimportantapplicationuseraccount，whoseschemahasimportanttables.Youareaskedtorecoveralltheobjectsintheschema.Oninvestigation，youfindthattheuseraccountwasdroppedat11：00a.m.andSunday’sbackupisthemostrecentbackup.Whichflashbackfeaturewouldyouuse？（）

单项选择题 A data file became corrupted in your database due to bad sectors on the disk. Because of corruption， you lost all the important tables in that data file. Which method would you use for recovery？（）