1.Thanks FOR  all you've done for me. I appreciate it…
2. You should spend your money ON travelling.
3. Is this car FOR sale?
4. Lapland is very popular AMONG skiers who do not mind queuing to ski lifts.
5. ON my way home I stopped on a petrol station.
6. What are you looking FOR? 
7. I prefer staying AT home TO a rainy day and read books.  prefer +verb-ing/noun TO +verb-ing/noun 
8. -Will you ski  tomorrow? –It depends ON the weather conditions.
9. Who is that boy smiling AT  you?
10. What is Helsinki famous FOR?
11. Angry Birds is the best game ON the European market. 
12. This project is very much similar TO Eva’s. Don’t you think so?
13. Will we find answers TO these questions?
14. I usually get up early IN the morning and go to bed late AT night (IN the night). 
15. He was born AT 8:15 IN the morning ON June, 18th, 1928  (ON + a day)