Réponse:
1) Farmers have been using dogs to find truffles in some districts.
2) Why the roof hasn't been mended before it fell in?
3) I have been told he was leaving France in August by somebody.
4) He will be find guilty by the court.
5) My shoes had been polished by somebody.
6) why were tomatoes and rotten egg were thrown by people.
7) Books may be keep for three weeks by students.
8) With what he wrote it?
9) The room is being cleaned by somebody.
10) The date of the meeting have been changed by them.
Hope it will help you.
