Past perfect simple and continuous 2

1. It __________ so quickly, I didn't notice.
   1.   ?    had happened
   2.   ?    had been happening
2. By the time they left town the mechanic __________ the car.
   1.   ?    had been repairing
   2.   ?    had repaired
3. __________ long before the taxi arrived?
   1.   ?    Had you been waiting
   2.   ?    Had you wanted
4. It seemed like somebody __________ a cake.
   1.   ?    had been cooking
   2.   ?    had cooked
5. When Tommy finally came the girls __________ for a few hours.
   1.   ?    had sung
   2.   ?    had been singing
6. After they __________ the good news they burst into laughter.
   1.   ?    had heard
   2.   ?    had been hearing
7. I __________ my document before the computer crashed.
   1.   ?    had saved
   2.   ?    had been saving
8. We __________ to open the door for five minutes when Jane found her key.
   1.   ?    had been trying
   2.   ?    had tried
9. After Sofie __________ her work, she went to lunch.
   1.   ?    had been finishing
   2.   ?    had finished
10. After the company __________ Joe, he began to work on his first project.
    1.   ?    had hired
    2.   ?    had been hiring