Вместо оборота с предлогом 'of' образуйте оборот с существительным в притяжательном падеже. Образец: the office of Mr.

the office of Mr. Black - Mr. Black\'s office

the children of these women – These women’s children

the room of my sister — My sister’s room

the pen of my brother — my brother’s pen

the book of Mary — Mary’s book

the table of Mr. Smith — Mr. Smith’s table

the dress of the girl — the girl’s dress

the ball of the boy — the boy\'s ball

the doll of the little girl — the little girl\'s doll

the horses of the man — the man\'s horses

the hen of Mary — Mary\'s hen

the plates of the lady — the lady\'s plates

the baby of the mother — the mother\'s baby