1. My friend's brothers
2. Ivanov's notebooks;
3. My son's book;
4. This engineesr's daughters' marks;
5. Kids' toys; 6. My mother's birthday;
7. My daughter's favorite cake;
8. His sister's letter;
9. My father's letters;
10. My friend's son;
11. Maria's older sister;
12. Our friends' kids;
13. Famous artist's painting;
14. This engineesr's wife;
15. Petrov's son's articles.