saluutt, est-ce que quelqu’un pourrait m’aider pour cet exo please ?? Mercii d’avance

1/ I have never forgotten that day.

2/ When I was a teenager, I have not realized the impact of the event.

3/ She has forgiven the people who attacked her that day.

4/ I have already heard her story. Two years ago, we studied Elizabeth Eckford's story with the English teacher.