Réponse :
Bonjour,
PASSIF =
BE ( conjugué au temps de la voix active ) + Participe passé passé
Toutes les phrases de l'exercice sont au prétérit, donc nous aurons
== > WAS / WERE + Participe passé
1) The land was claimed for Britain by capitain Cook in 1770.
2) Australia was founded by the British in 1788.
3) Australia was used as a prison by the British.
4) Prisoners were sent there by the British.
5) The Aborigines' land was taken by the British.
6) Independence from the British was gained by Australia in 1901.
7) Great Britain was joined by Australia in the first two world wars.
8) Australia was bombed by Japan in WWII.