Réponse:

1)

They have never been to London .

I have been sick for two weeks .

We have already seen that movie .

She hasn't seen him since last summer.

We have bought a new house last week.

2)

Have you ever fought in public?

Have you already met a celebrity?

Have you ever been to America?

Have you ever bullied someone?

3)

-The boy has been hit by his classmates.

-The children have forgiven their bullies.

-The girl has been held responsible for the accident.

-The school has forbidden the use of mobiles because of cyberbulliying.