1. What was the man doing, when somebody knocked at the door? 2. What was he waiting for? 3. What was the boy doing? 4. What were the students doing when you opened the door? 5. What was the girl eating when you came in? 6. Who was she looking for? 7. What were the students discussing? 8. What was the man doing when the clock struck ten? 9. How was the weather when you went out? 10. What was the boy doing?