what is the callsign whtat uses 7bu?
CREATE TABLE table_name_9 (callsign VARCHAR, on_air_id VARCHAR)
SELECT callsign FROM table_name_9 WHERE on_air_id = "7bu"
### Context: CREATE TABLE table_name_9 (callsign VARCHAR, on_air_id VARCHAR) ### Question: what is the callsign whtat uses 7bu? ### Answer: SELECT callsign FROM table_name_9 WHERE on_air_id = "7bu"