Which two statements are true about WHERE and HAVING clauses? （）
A:A WHERE clause can be used to restrict both rows and groups.
B:A WHERE clause can be used to restrict rows only.
C:A HAVING clause can be used to restrict both rows and groups.
D:A HAVING clause can be used to restrict groups only.
E:A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.
F:A HAVING clause CANNOT be used in subqueries.
出自：Oracle认证