-- Database schema
| race : Race_ID [ INT ] primary_key , Name [ TEXT ] , Class [ TEXT ] , Date [ TEXT ] , Track_ID [ TEXT ] race.Track_ID = track.Track_ID | track : Track_ID [ INT ] primary_key , Name [ TEXT ] , Location [ TEXT ] , Seating [ INT ] , Year_Opened [ INT ] |
-- -- Find the locations where have both tracks with more than 90000 seats and tracks with less than 70000 seats.

SELECT LOCATION FROM track WHERE seating  >  90000 INTERSECT SELECT LOCATION FROM track WHERE seating  <  70000;