Перефразируйте, употребляя притяжательный падеж. Получившиеся словосочетания переведите на русский язык. : The flat of my sister, the room of these people, the son of her mother, the food of those dogs, the name of this man, the hobby of these gentlemen, the mark of our student, the work of the man, the ball of my child, the friend of Susan.

The flat of my sister=my sisters flat

the room of these people = these peoples room

the son of her mother=her mothers son

the food of those dogs=those dogs food

the name of this man = this mans name

the hobby of these gentlemen = these getlemens hobby 

the mark of our student = our students mark

the work of the man = the mans work

the ball of my child = my childs ball

the friend of Susan = Susans friend