1. When the police STOPPED / WERE STOPPING Smith's car for a routine check, they realized that he HAD ROBBED / ROBBED the bank.

2. I woke up in the middle of the night and TURNED ON / WAS TURNING ON the light. Someone or something CLIMBED / WAS CLIMBING in my window!

3. Unfortunately Jan ARRIVED / WAS ARRIVING at the station at 3.25, and found that she HAD MISSED / MISSED the train.

4. The doctors TRIED / HAD BEEN TRYING their best, but while they were performing the operation, the patient DIED / WAS DYING.

5. We'd been watching the film for half an hour before we realized that we HAD MADE / WERE MAKING a terrible mistake. We HAD GONE / WENT into the wrong cinema!

6. On the morning of the accident, Mr Davis HAD JUST FINISHED / JUST FINISHED a night shift at a local factory, and HADN'T HAD / DIDN'T HAVE any sleep for 24 hours.

7. I'm sorry I DIDN'T ANSWER / WASN'T ANSWERING the phone earlier, but I HAD BEEN PAINTING / WAS PAINTING the ceiling in my bedroom.

8. The office Marlowe was visiting was on the 15th floor, and unfortunately the lift WASN'T WORKING / HADN'T BEEN WORKING, so by the time he arrived at the top of the stairs, he WAS / HAD BEEN out of breath.

9. On Christmas morning when they WOKE UP / WERE WAKING UP, the children looked eagerly out of the window. It HAD BEEN SNOWING / SNOWED, and the garden was covered in a thick white carpet.

10. After the two film stars LANDED / WERE LANDING at the small airport, they left quickly in a van that HAD BEEN WAITING / WAS WAITING for them since the early morning.