CREATE TABLE "regular_season" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "game_site" text,
  "record" text,
  "attendance" real
);

Question: Who was the opponent before week 6 at cleveland municipal stadium?
SQL: SELECT "opponent" FROM "regular_season" WHERE "week"<6 AND "game_site"='cleveland municipal stadium';