user: Question: Which circuit did Alfa Romeo win?
Columns: ['Name', 'Circuit', 'Date', 'Winning driver', 'Winning constructor', 'Report']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Garda Circuit', 'Salò', '22 May', 'Eugenio Silvani', 'Bugatti', 'Report']
SQL:

assistant: SELECT "Circuit" FROM "Table" WHERE "Winning constructor" = 'Alfa Romeo';