[多项选择]Which three statements about subqueries are true? （）
A. A main query can have more than one subquery.
B. A subquery can have more than one main query.
C. The subquery and main query must retrieve data from the same table.
D. The subquery and main query can retrieve data from different tables.
E. Only one column or expression can be compared between the subquery and main query.
F. Multiple columns or expression can be compared between the subquery and main query.

[多项选择]Which three statements about subqueries are true? （）
A. A main query can have more than one subquery.
B. A subquery can have more than one main query.
C. The subquery and main query must retrieve data from the same table.
D. The subquery and main query can retrieve data from different tables.
E. Only one column or expression can be compared between the subquery and main query.
F. Multiple columns or expression can be compared between the subquery and main query.

[多项选择]Which two statements about subqueries are true?（）
A. A single row subquery can retrieve data from only one table.
B. A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.
C. A SQL query statement can display data from table B that is referred to in its subquery, without including table B in its own FROM clause.
D. A single row subquery can retrieve data from more than one table.
E. A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.
F. A multiple-row subquery cannot be used in a condition where the LIKE operator is used for comparison.

[多项选择]Which three are true about MPLS LSP establishment using RSVP?（） (Choose three.)
A. Ordered Control
B. Independent Control
C. Down Stream Unsolicited
D. Liberal Label Management
E. Down Stream On Demand

[多项选择]Which three are true about the large pool for an Oracle database instance that supports shared serverconnections?（）
A. Allocates memory for RMAN backup and restore operations
B. Allocates memory for shared and private SQL areas
C. Contains a cursor area for storing runtime information about cursors
D. Contains stack space
E. Contains a hash area performing hash joins of tables

[多项选择]Which three are true?（）
A. A MERGE statement is used to merge the data of one table with data from another.
B. A MERGE statement replaces the data of one table with that of another.
C. A MERGE statement can be used to insert new rows into a table.
D. A MERGE statement can be used to update existing rows in a table.

[多项选择]Which three statements are true about using flashback database in a multitenant container database(CDB)?（）
A. The root container can be flashed back without flashing back the pluggable databases (PDBs).
B. To enable flashback database, the CDB must be mounted.
C. Individual PDBs can be flashed back without flashing back the entire cdb.
D. The DB_FLASHBACK RETENTION_TARGET parameter must be set to enable flashback of the cdb.
E. A CDB can be flashed back specifying the desired target point in time or an SCN, but not a restore point.