List all of the restaurant addresses from an unknown region.
restaurant address refers to street_num, street_name; unknown region refers to region = 'unknown'
SELECT T2.street_name FROM geographic AS T1 INNER JOIN location AS T2 ON T1.city = T2.city WHERE T1.region = 'unknown'
database name:db_id restaurant
geographic table geographic Cols: city dtype text, country dtype text, region dtype text, 
generalinfo table generalinfo Cols: id restaurant dtype integer, label dtype text, food type dtype text, city dtype text, review dtype real, 
location table location Cols: id restaurant dtype integer, street number dtype integer, street name dtype text, city dtype text, 
