1. We had been sleeping for 12 hours when he woke us up.
2. They had been waiting at the station for 90 minutes when the train finally arrived.
3. We had been looking for her ring for two hours and then we found it in the bathroom.
4. I hadn`t been walking for a long time, when it suddenly began to rain.
5. How long had she been learning English before she went to London?
6. He had been driving less than an hour when he ran out of petrol.
7. They were very tired in the evening because they had been helping on the farm all day.
8. I hadn`t been working all day; so I wasn't tired and went to the disco at night.
