What circuit did Clay Regazzoni win?
CREATE TABLE table_1140090_6 (circuit VARCHAR, winning_driver VARCHAR)
SELECT circuit FROM table_1140090_6 WHERE winning_driver = "Clay Regazzoni"
### Context: CREATE TABLE table_1140090_6 (circuit VARCHAR, winning_driver VARCHAR) ### Question: What circuit did Clay Regazzoni win? ### Answer: SELECT circuit FROM table_1140090_6 WHERE winning_driver = "Clay Regazzoni"