Table: t_1950_swiss_grand_prix
Columns: driver
entrant
constructor
chassis
engine
tyre

Question: Which engine has the entrant scuderia ferrari and is driven by Raymond Sommer?
SQL: SELECT "engine" FROM t_1950_swiss_grand_prix WHERE "entrant" = 'scuderia ferrari' AND "driver" = 'raymond sommer'

Question: What Chassis does Reg Parnell drive?
SQL: SELECT "chassis" FROM t_1950_swiss_grand_prix WHERE "driver" = 'reg parnell'