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單項(xiàng)選擇題

Which statement is true regarding synonyms?（）

A.Synonyms can be created only for a table 
B.Synonyms are used to reference only those tables that are owned by another user 
C.A public synonym and a private synonym can exist with the same name for the same table 
D.The DROP SYNONYM statement removes the synonym, and the table on which the synonym has been created becomes invalid

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