Answer:
1. whether (it is) heated or not
2. did he charge me too much
3. compared with mine
4. half as much (money)
5. to attribute their children’s success to
6. the match has been called off
7. but I‘ll make an exception in your case
8. We’ll have to put off (going on) vacation
9. I didn‘t mean to give you a lot of trouble
10. I don’t really want to go to the party
11. It is not until they lose it
12. with dirty clothes
13. With many friends absent
14. What impressed me the most
15. less powerful than the ones we have made