CREATE TABLE table_37917 ("Date" TEXT, "Score" TEXT, "Set 1" TEXT, "Set 2" TEXT, "Set 3" TEXT, "Total" TEXT)

Which Set 2 has a Date of 25 may, and a Set 3 of 21 25?
SELECT "Set 2" FROM table_37917 WHERE "Date" = '25 may' AND "Set 3" = '21–25'
SELECT "Set 2" FROM "table_37917" WHERE "Date" = '25 may' AND "Set 3" = '21–25'