1. returned
2. picked
3. knew
4. has achieved
5. has been contributing
6. have established (кажется можно написать без have, но лучше напиши с)
7. took
8. tamed
9. were
10. took
11. worked
12. disappeared
13. was loving (может быть has been loving)
14. wrote
15. were living (также можно написать lived, я не вижу ошибки такого писания)