CREATE TABLE city (City_ID VARCHAR(255), Population INTEGER); CREATE TABLE farm_competition (Theme VARCHAR(255), Host_city_ID VARCHAR(255))
Please show the themes of competitions with host cities having populations larger than 1000.
    
SQL: SELECT T2.Theme FROM city AS T1 JOIN farm_competition AS T2 ON T1.City_ID = T2.Host_city_ID WHERE T1.Population > 1000