1. Water consists …of……… hydrogen and oxygen.

2. She lived independently …with……… her parents.

3. Santa Claus is based ……on…. the description of Saint Nicholas in the poem.

4. We give each other presents ……at……. Christmas.

5. Don’t sit …on……. the floor.

6. I’m going away ……at……. the end of January.

7. I met Tom ……in……. the street yesterday.

8. They sent me a cheque ……for……. $ 50.

9. There has been some decrease ……of……. military spending this year.

10. Nobody knows what the cause ……of……. the explosion was.

11. Do you think we’ll find a solution ……to……. this problem?

12. Have you ever read any books ……of……. Mark Twain?

13. It’s unreasonable ……for……. you to expect her to love you at first sight.

14. They were furious ……with…….me ……at…….not inviting them to the party.

15. Were you disappointed ……at…….your examination results?

16. Everybody was shocked ……at…….the news.

17. She is scared …of……….going out alone.

18. I’m not ashamed …of……….what I did.

19. My sister won’t have dinner .......until........ 11.30 p.m.

20. She is engaged ……to…….an American.