Respuesta:
a) mark and kate were in the park with their granfather
they were in the park with him.
B) Mary was in the kitchen with her mother.
she was in the kitchen with her .
C) Paul and I were in the party with my friends.
we were in the party with ---.
D) Peter was in the cinema with him father.
he was in the cinema with him
Explicación:
no se si esta bien pero ahi te lo dejo :)