=>
I/
1. had/would not have to
2. doesn't arrive
3. will not refund
4. would you feel
5. visit
6. were not
7. hadn't been
8. told
9. spoke
10. didn't complain
11. don't revise
12. would you work
13. enters/goes off
14. would travel/could afford
15. would have given

II/
1. If you take exercise regularly, you will get fit.
2. If I got a dictionary, I could look the word up.
3. If I had his number, I would phone him.

4. If David were not so clumsy, he wouldn't have so many accidents.
5. If I were not so busy, I woould write to my friends regularly.
6. If Sandra arrives a bit early, she can help you get things ready.
7. If the bus were not always so crowded, I would ride it to school every morning.
8. If the office is closed, Mark won't be able to get in.
9. If people realised how important it is to conserve energy, they would do something about it.
10. If you want a chat, give me a ring.
11. If it were not raining, we would finish the game.
12. If the driver in front hadn't stopped suddenly, the accident would not have happened.
13. If the airport hadn't been closed, Sarah would have been able to fly to Rome.
14. If Carol had answered the phone, she wouldn't have been studying.
15. If I had had an umbrella, I wouldn't have got very wet in the rain.