Table: gunsmoke_episodes
Columns: series
season
title
director
writer_s
airdate

Question: Who wrote the episode with series number 56?
SQL: SELECT "writer_s" FROM gunsmoke_episodes WHERE "series" = 56

Question: What is largest series number for the episode that aired February 16, 1957?
SQL: SELECT MAX("series") FROM gunsmoke_episodes WHERE "airdate" = 'February 16, 1957'

Question: Who directed the episodes that aired December 15, 1956? 
SQL: SELECT "director" FROM gunsmoke_episodes WHERE "airdate" = 'December 15, 1956'

Question: Who wrote the episode that aired December 1, 1956? 
SQL: SELECT "writer_s" FROM gunsmoke_episodes WHERE "airdate" = 'December 1, 1956'