context: Some episodes have been returned to the BBC from the archives of other countries who bought prints for broadcast, or by private individuals who acquired them by various means. Early colour videotape recordings made off-air by fans have also been retrieved, as well as excerpts filmed from the television screen onto 8 mm cine film and clips that were shown on other programmes. Audio versions of all of the lost episodes exist from home viewers who made tape recordings of the show. Short clips from every story with the exception of Marco Polo, "Mission to the Unknown" and The Massacre of St Bartholomew's Eve also exist.
question: কিভাবে বিবিসি হারিয়ে যাওয়া পর্বের অডিও সংস্করণ পেল?
answers: home viewers who made tape recordings of the show home viewers who made tape recordings of the show home viewers who made tape recordings