Question

Помогите пожалуйста (
Замените существительное с предлогом of формой притяжательного падежа :
1.The book of my friend Peter
2.the house of my grandparents
3.the opinion of the lawyer
4.the room of my children
5.the surname of Helen and Peter
6.the poems of Pushkin
6.the son of my brother Paul
7.The marks of the students 
8.the children of these women
9.the library of my father and mother

Answer 1

My friend's book.
My grandparents' house.
The lawyer's opinion.
My children's room.
Helen and Peter's surname.
Pushkin's poems.
My brother Paul's son.
The students' marks.
These women's children.
My father and mother's library.