Ответ:

  1. Who is she? — She is Oleg’s grandmother.
  2. Who are they? — They are Vlad’s grandparents.
  3. Who is Alla Petrova? — Alla Petrova is Dima’s mother.
  4. Who is Ivan Sergeevich? — Ivan Sergeevich is my grandfather.
  5. Who are they? — They are Galina’s sisters.
  6. Who are you? — I am Sveta and Lena’s brother.
  7. Who are you? — We are Inga’s friends.