CREATE TABLE table_6703 ("Outcome" CLOB, "Date" CLOB, "Tournament" CLOB, "Surface" CLOB, "Partner" CLOB, "Opponent" CLOB, "Score" CLOB)

Which Opponent had a Surface of hard, and a Partner of maria elena camerin?
SELECT "Opponent" FROM table_6703 WHERE "Surface" = 'hard' AND "Partner" = 'maria elena camerin'
SELECT "Opponent" FROM "table_6703" WHERE "Partner" = 'maria elena camerin' AND "Surface" = 'hard'