Past Simple or Present Perfect?

1. He (already/ to see) this film.
2. He (to see) it when he was in London.
3. When (you /to meet) Harry? - I (to meet) him the day before yesterday.
4. …(you /ever /to see) a giant butterfly?
5. Dan isn’t at home at the moment. He (to go) to the stadium.
6. Carol (to buy) a new camera last week.
7. I (to be) to the zoo 2 weeks ago.
8. I (to be) to the zoo before.