CREATE TABLE table_204_455 (id DECIMAL, "rd." DECIMAL, "grand prix" TEXT, "date" TEXT, "location" TEXT, "pole position" TEXT, "fastest lap" TEXT, "winning driver" TEXT, "constructor" TEXT, "report" TEXT)

what was the only grand prix to be won by benneton ford ?
SELECT "grand prix" FROM table_204_455 WHERE "constructor" = 'benetton-ford'
SELECT "grand prix" FROM "table_204_455" WHERE "constructor" = 'benetton-ford'