sample answer

1. if the police had caught that thief, he wouldn't have committed more crimes.
2. i wouldn't have asked you to read this book if i had known you were not interested in the topic.
3. if i hadn't listened to that lecture, i wouldn't have understood the concept.
4. if you had phoned me yesterday, i would have been able to join you for lunch.
5. they would have called the police if they had witnessed the accident.