1. Where had Sandy been working before finding a job in Switzerland?
2. How long had Demi and Sylvia been living together before Demi moved to another city?
3. Who had been sending the letters before I was employed?
4. What had he been doing before the police knocked on his door?
5. What had I been doing for an hour before I was late for work?
6. How long had Mark's family been looking for him before they found him at his friend's house?
