user: Question: Which chassis has an Alfa Romeo Flat-12 engine.
Columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1972.0, 'Team Williams-Motul', 'March 711', 'Cosworth V8', 3.0]
SQL:

assistant: SELECT "Chassis" FROM "Table" WHERE "Engine" = 'Alfa Romeo Flat-12';