Ответ:
1) Have many schools been constructed this year?
Many schools have not been constructed this year.
2) Has the new project been already finished?
The new project has not been finished.
3) Has our library been turned into a shopping centre?
Our library has not been turned into a shopping centre.
4) Has the problem been already discussed?
The problem has not been discussed.
5) Have the letters been posted?
The letters have not been posted.
Объяснение: