CREATE TABLE table_34770 ("Event" TEXT, "Gold" TEXT, "Silver" TEXT, "Bronze" TEXT, "4th place" TEXT)

Who won the gold when Bertil Ahlin Sweden won the silver?
SELECT "Gold" FROM table_34770 WHERE "Silver" = 'bertil ahlin sweden'
SELECT "Gold" FROM "table_34770" WHERE "Silver" = 'bertil ahlin sweden'