Переделать предложения 8. the letter of peter 9. the room of my frienb 10. the hand tag of the monen 11. the flat of my sister 12. the children of my brothen 13. the room of the bops

8. Peter's letter.
9. My friend's room.
10. ???
11. My sister's flat.
12. My brother's children.
13.Boy's room.