A.Listeners use only the TCP/IP protocol.
B.Multiple listener processes can run simultaneously on a host.
C.Multiple database instances can be registered with a single listener.
D.The listener-related errors can be traced only at the administrative level.
E.Only one database instance can be registered with a single listener at any time

A.You must shut down the database instance to perform the backups.
B.You must configure the Flash Recovery Area （FRA） for the database.
C.You can perform complete database backups without closing the database.
D.All the previous closed database backups including control files become invalid after you configure thedatabase to ARCHIVELOG mode.