1. had got me a birthday present, I would have got her one.

2. hadn't made a mistake with our order, we would have paid them on time

3. the climate wasn't undergoing such radical changes, scientists wouldn't be worried.

4. California have become an important area if they hadn't found gold there?

5. hadn't been for the sunset, the tourists wouldn't have been attracted to that place

6. hadn't been a traffic jam on the motorway, I wouldn't have been late for my interview

7. you, I would use a sunblock and then you won't go red

8. had paid attention to the road, the accident wouldn't have happened

C

1. hadn't done

2. would have never had

4. ask

5. are booked

6. will have

6. get

7. have happened

8. had been

9. wander

10. be

11. starts

12. have happened