Task: Question Generation
Input (English): Context: But it could have been a shoe squeaking . It could have been a stomach gurgle . It could have been a burp . It could have been the leather on someone 's chair moving . And .. it could have been a fart . Of course , a sound like that ... it could have been a million things . I did n't think much of it , until she said:"OH ! Excuse me ! ".
Output (English): What was the sound ?