Table: tv_episode_data_31
Columns: series
season
title
directed_by
written_by
original_air_date
u_s_viewers_millions

Question: What episode titles have 17.93 million U.S. viewers?
SQL: SELECT "title" FROM tv_episode_data_31 WHERE "u_s_viewers_millions" = '17.93'

Question: What episode titles have 20.94 million U.S. viewers?
SQL: SELECT "title" FROM tv_episode_data_31 WHERE "u_s_viewers_millions" = '20.94'

Question: In what seasons did Kate Woods direct Without A Trace?
SQL: SELECT "season" FROM tv_episode_data_31 WHERE "directed_by" = 'Kate Woods'

Question: Who wrote Season 8?
SQL: SELECT "written_by" FROM tv_episode_data_31 WHERE "season" = 8