user: Question: Which chassis was used in 1971?
Columns: ['Year', 'Team', 'Chassis', 'Engine', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1959.0, 'Team Lotus', 'Lotus 16', 'Climax Straight-4', 0.0]
SQL:

assistant: SELECT "Chassis" FROM "Table" WHERE "Year" = 1971.0;