CREATE TABLE "by_year" (
  "year" text,
  "designated_grand_prix" text,
  "track" text,
  "250_cc" text,
  "350_cc" text,
  "500_cc" text,
  "report" text
);

Question: What year did Freddie Frith win the 350cc and Enrico Lorenzetti win the 500cc?
SQL: SELECT "year" FROM "by_year" WHERE "350_cc"='freddie frith' AND "500_cc"='enrico lorenzetti';

Question: What track was used in 1926?
SQL: SELECT "track" FROM "by_year" WHERE "year"='1926';

Question: Who won the 250cc in 1927?
SQL: SELECT "250_cc" FROM "by_year" WHERE "year"='1927';

Question: What grand prix was held at Granollers?
SQL: SELECT "designated_grand_prix" FROM "by_year" WHERE "track"='granollers';

Question: Who won the 350cc at Sachsenring?
SQL: SELECT "350_cc" FROM "by_year" WHERE "track"='sachsenring';