1. She had been writing the essay for 2 hours, when I called her.
2. When we came, he had been playing the violin for an hour.
3. How long had you been staying at your friend’s place, when received our message?
4. How long had you been working, when you retired?
5. Sam had been looking at Jane for several minutes, when she opened her eyes.
6. She had been reading the book for 3 hours, when decided to take rest.
7. I had been watching the novice for an hour, when he turned around and greeted me.
