exercise 1:

1C 2D 3A 4D 5B 6D 7A

exercise 2:

1. which 2.whose 3.who 4.which 5.who 6.who 7.which 8. who 9. whose 10. whose

exercise 3:

1. which-> that

2. whom->who

3. that->who

4. that -> which

5. that-> who

exercise 4:

1. The girl whose bike broke down looked very upset.

2. His grandmother who was a hard-working woman had a great influence on his life.

3. Mai is interested in physics which I don't like.

4. I will always remember the teacher who taught me how to read and write.

5. He was sitting on a chair which was uncomfortable.

6. Let me see the pictures which you took at Peter's wedding.

7. Do you know that lady whose car I repaired?

8.  That girl whom Tom is in love with is Swedish.

9. Some people I never travel with drive drunk.

10. The man whom the police have caught stole $ 10 000 from a bank.