A.The backup will consist of used data blocks only.
B.The database must be shut down to accomplish the backup.
C.The backup can be accomplished without shutting down the database.
D.The backup will contain all database files that have never been backed up

A.The user SKD can grant only the MGR_ROLE role to other users， but not the privileges in it.
B.The user SKD can revoke the MGR_ROLE only from the users for whom he/she is the grantor.
C.The user SKD can grant the privileges in the MGR_ROLE role to other users， but not with ADMIN OPTION.
D.The user SKD can grant the privileges in the MGR_ROLE role to other users， but cannot revoke privilegesfrom them