Table: t_1938_gp_season
Columns: name
circuit
date
winning_driver
winning_constructor
report

Question: Which circuit did Raymond Mays win?
SQL: SELECT "circuit" FROM t_1938_gp_season WHERE "winning_driver" = 'raymond mays'

Question: Which Circuit did Johnny Wakefield win?
SQL: SELECT "circuit" FROM t_1938_gp_season WHERE "winning_driver" = 'johnny wakefield'