CREATE TABLE "table1_21172539_1" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real,
  "u_s_viewers_millions" text
);

Question: What date did the episode with a production code of 4301085 originally air?
SQL: SELECT "original_air_date" FROM "table1_21172539_1" WHERE "production_code"=4301085;

Question: What date did episode 15 of the season originally air?
SQL: SELECT "original_air_date" FROM "table1_21172539_1" WHERE "no_in_season"=15;

Question: How many items are listed under the column of U.S. viewers for episode "Bite Me"?
SQL: SELECT COUNT("u_s_viewers_millions") FROM "table1_21172539_1" WHERE "title"='\"Bite Me\"';