You plan to use static database registration for a new listener when you create it.What could be the two reasons for this？（）

• A、More than one database is to be registered with the listener.
• B、The users will connect the database by using the host naming method.
• C、The Oracle Enterprise Manager is to be used to monitor an Oracle9i database.
• D、The database that is to be registered with the listener is configured in shared server mode.
• E、The listener is not configured on the default port of 1521 and the instance is not configured to register with a nondefault port.