Exercise 4.
1 heat / will start или starts,
2 hadn't been / wouldn't have been,
3 had stayed / would have had,
4 loses / will resign,
5 hadn't gone / would have never met,
6 were / would use,
7 gets,
8 would have been,
9 are broken / will be,
10 had known / would have helped,
11 would have had / hadn’t been driving