Réponse:

ex 1 :

- I don't like films which last more than two hours.

- J.K. Rowling is the person who wrote the Harry Potter books.

- Do you know the girl who saw in the café ?

- Is this the train station which goes to the bus ?

- Did you buy that T-shirt which you liked so much ?

ex 2 :

1) who/ 2) which/ 3) that/ 4) who/ 5) that

ex 3 :

1) who/which 2) who/ 3) with/ 4) who/which/ 5) that/ 6) who/which