What is the Surface of the match with a Score in the final of 5–7, 6–7 (2–7)?
CREATE TABLE "singles_11_5_6" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent_in_the_final" text,
  "score_in_the_final" text
);
SELECT "surface" FROM "singles_11_5_6" WHERE "score_in_the_final"='5–7, 6–7 (2–7)';