помогите с английским с пассивными глаголами(Ответы там неправильные написаны,вообще эту тему не понимаю:(Заранее спасибо большое

1. will be published
2. was the telephone invented
3. will be posted
4. Has your composotion been written
5. has been played
6. must be answered
7. was being painted
8. are being discussed
9. have been found
10. could be seen
11. is used
12. had been done