What is Party, when District is less than 10, when Took Office is less than 1991, and when Home Town is Mount Pleasant?
CREATE TABLE "senate" (
  "senator" text,
  "party" text,
  "district" real,
  "home_town" text,
  "took_office" real
);
SELECT "party" FROM "senate" WHERE "district"<10 AND "took_office"<1991 AND "home_town"='mount pleasant';