You plan to use static database registration for a new listener when you create it.What could be the two reasons for this？（）
- AMore than one database is to be registered with the listener.
- BThe users will connect the database by using the host naming method.
- CThe Oracle Enterprise Manager is to be used to monitor an Oracle9i database.
- DThe database that is to be registered with the listener is configured in shared server mode.
- EThe listener is not configured on the default port of 1521 and the instance is not configured to register with a nondefault port.