CREATE TABLE "250cc_classification" (
  "rider" text,
  "manufacturer" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);

Question: What kind of  Manufacturer has a Laps smaller than 20 and a Grid of 21
SQL: SELECT "manufacturer" FROM "250cc_classification" WHERE "laps"<20 AND "grid"=21;