Задание 12.
1) who – used for people (a),
2) which – used for things (c),
3) whose – show possession (b).
Задание 13.
1) уже сделано в качестве примера,
2) she lives in a big house which is near the park,
3) Steven is a lawyer whose office is in Baker Street,
4) Claire is a model who has been in many fashion shows,
5) Sarash is wearing a nice dress which fits her perfectly.