CREATE TABLE table_31900 ("Outcome" TEXT, "Date" TEXT, "Surface" TEXT, "Partner" TEXT, "Opponents" TEXT, "Score" TEXT)

What was the surface for the game that had a partner of vania king?
SELECT "Surface" FROM table_31900 WHERE "Partner" = 'vania king'
SELECT "Surface" FROM "table_31900" WHERE "Partner" = 'vania king'