1) My child had eaten too much chocolate that is why he was so ill.
2) The car worked, but the mechanic had been repairing it for a few hours.
3) When I arrived at the cinema, the film had started.
4) The door was still wet. My father had painted it.
5) We were late for the plane because we had forgotten our passports.
6) They had been building the house for many years already before they finished.
Ответ: смотри выше