Murphy, Unit 16, 16.2

1. We had been playing for half an hour when it started to rain.
2. I had been waiting for 20 minutes when I realised that I was in the wrong restaurant.
3. At the time the factory closed down, Sarah had been working there for five years.
4. The orchestra had been playing for about ten minutes when a man in audience suddenly started shouting.
5. I began walking along the road. I had been walking for about half an hour when I saw my friend Michael.