Which To par has a Country of united states, and a Score of 71-70=141?
CREATE TABLE "second_round" (
  "place" text,
  "player" text,
  "country" text,
  "score" text,
  "to_par" text
);
SELECT "to_par" FROM "second_round" WHERE "country"='united states' AND "score"='71-70=141';