{1:SHORTANSWER:~%100%had started#A past event that happened before another past event; the past perfect is used in the subordinate clause with the conjunction “since” indicating the point in the past from which another event started~%100%'d started#A past event that happened before another past event; the past perfect is used in the subordinate clause with the conjunction “since” indicating the point in the past from which another event started~%100%had started---------#A past event that happened before another past event; the past perfect is used in the subordinate clause with the conjunction “since” indicating the point in the past from which another event started~%100%’d started#A past event that happened before another past event; the past perfect is used in the subordinate clause with the conjunction “since” indicating the point in the past from which another event started}