Table: tv_episode_data_9
Columns: no_in_season
no_in_series
title
directed_by
written_by
original_air_date
u_s_viewers_million

Question: How many millions of U.S. viewers watched "Brace for Impact"?
SQL: SELECT "u_s_viewers_million" FROM tv_episode_data_9 WHERE "title" = '"Brace for Impact"'

Question: How many millions of U.S. viewers watched the episode that first aired on March 31, 2013?
SQL: SELECT "u_s_viewers_million" FROM tv_episode_data_9 WHERE "original_air_date" = 'March 31, 2013'

Question: Who wrote the episodes that were viewed by 2.12 million viewers?
SQL: SELECT "written_by" FROM tv_episode_data_9 WHERE "u_s_viewers_million" = '2.12'