CREATE TABLE "past_production" (
  "headphone_model" text,
  "headphone_class" text,
  "sensitivity_d_b" text,
  "impedance_ohms" real,
  "driver_matched_d_b" text,
  "construction" text,
  "earpads" text,
  "termination" text,
  "succeeded_by" text
);

Question: What is the headphone model with a plastic construction and a prestige headphone class?
SQL: SELECT "headphone_model" FROM "past_production" WHERE "construction"='plastic' AND "headphone_class"='prestige';

Question: What earpads does the headphone with plastic contruction and was succeeded by igrado have?
SQL: SELECT "earpads" FROM "past_production" WHERE "construction"='plastic' AND "succeeded_by"='igrado';

Question: What are the earpads of the headphone with a plastic construction, an unknown sensitivity, and was succeeded by sr325?
SQL: SELECT "earpads" FROM "past_production" WHERE "construction"='plastic' AND "sensitivity_d_b"='unknown' AND "succeeded_by"='sr325';

Question: What is the headphone model which was succeeded by sr325?
SQL: SELECT "headphone_model" FROM "past_production" WHERE "succeeded_by"='sr325';