1. He asked me if I could guess who had rung me up.
2. He asked me if I knew how far we were from the camp.
3. He asked me if I had any idea where it could be.
4. He asked me if I remembered who had written that poem.
5. He asked me whether (if) I would go to the theatre if he got tickets.
6. He asked me if I had heard when they would arrive.
7. He asked me what I thought Sergei was doing at that time.
8. He asked me if I knew what problem they would discuss.
9. He asked me if I could tell him what the time was.
10. He asked me if I knew which was the plate I had used.
11. He asked me if I thought he might take an apple.
12. He asked me if I was sure I had nothing else he could read.