Ответ:

  1. Tom and I have got a nice room.
  2. Mary is at home.
  3. Where is my bag? It is on the table.
  4. I have got a new book in my bag. It has got a kitten.
  5. My friend has got a kitten.
  6. She has got two brothers. They have got twelve computers in this classroom.
  7. We have got twelve computers in this classroom.
  8. Mary is a very pretty girl.

Правило: to be употребляется для обозначения состояния, места или признака; have got / has got — для обозначения обладания.