CREATE TABLE gymnast (Gymnast_ID VARCHAR(255)); CREATE TABLE people (Hometown VARCHAR(255), People_ID VARCHAR(255))
What are the hometowns that are shared by at least two gymnasts?
    
SQL: SELECT T2.Hometown FROM gymnast AS T1 JOIN people AS T2 ON T1.Gymnast_ID = T2.People_ID GROUP BY T2.Hometown HAVING COUNT(*) >= 2