Whose ruler is this?(Masha)
It's Masha's ruler
Whose notebook is this? (Liza)
It's Liza's notebook.
Whose bag is this? (Frank)
It's Frank's bag.
What's this? (Dog - ball)
It's dog's ball.
Whose ruber is this?(Anya)
It's Anya's rubber
Whose desk is this?(Vika)
It's Vika's desk
Whose pencil case is this? (David)
It's David's pencil case.