Ответ:
1.He had watched
Had he watched this TV programme befor his parwnts came home?
2. John and Andrew had got to the hotel befor night.
When had they got to the hotel?
3. A group of tourists had visited this cathedral ...
When had the group visited this cathedral?
4. His brother had moved ...
When had he moved?
5. I had met ...
When had I met?