очень срочно, пожалуйстаа

7.have announced
8.were stolen
9.have been valued
10.were taken
11.didn't go off
12.weren't discovering
13.had been found

2.When did the theft discover?
3.What have been stolen?
4.Have experts valued the paintings?
5.When were taken the paintings according to police information?
6.Had clues been found?