a) 1. i got home, heard
2. was claiming
3. crashed, i was printing out
4. was taking off, i started
5. wanted, chose
6. used to have, combined
7. arrived, was waiting
8. knocked, and came
9. were arguing, lost
10. i was, visited
b) 1. didn't use
2. i haven't forgotten
3. used to produce
4. i had seen
5. already left
6. used to go skiing
7. the meeting finished
