Ответ:
1.We lighted the candles
because the light had gone off.
first action: the light had gone off.
2.When I got home I discovered
that somebody had broken into my flat.
first action: somebody had broken into my flat.
3.The patient had died before
the ambulance reached the hospital.
first action: The patient had died.
4. Billy had eaten all the cakes by
the time the other children arrived at the party.
first action: Billy had eaten all the cakes.