{1:SHORTANSWER:~%100%had been listening#An event that continued for some time in the past before another past event~%100%’d been listening#An event that continued for some time in the past before another past event~%100%'d been listening#An event that continued for some time in the past before another past event~%100%had been listening--#An event that continued for some time in the past before another past event}