Table: tvb_series_2008
Columns: airing_date
number_of_episodes
hd_format
highest_average_point_ratings
genre
official_website

Question: What was the airing date when the number of episodes was larger than 20 and had the genre of costume action?
SQL: SELECT "airing_date" FROM tvb_series_2008 WHERE "number_of_episodes" > 20 AND "genre" = 'costume action'

Question: What are the number of episodes when the genre is modern drama and the highest average ratings points are 28?
SQL: SELECT AVG("number_of_episodes") FROM tvb_series_2008 WHERE "genre" = 'modern drama' AND "highest_average_point_ratings" = 28