Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_91 ( channels___analog___digital__ VARCHAR, first_air_date VARCHAR, region_served VARCHAR )

### Question ###
What channels first aired on 31 December 1990 in the Southern Downs region?

### Accurate SQL ###

SELECT channels___analog___digital__ FROM table_name_91 WHERE first_air_date = "31 december 1990" AND region_served = "southern downs"