1.People should send their complaints to the head office.
Complaints should be sent to the head office.
2. We must take good care of books borrowed from the library.
 Books borrowed from the library must be taken good care of.
3. Must we finish the test before ten?
Must the test be finished before ten?
4. They can open this safe.
this can be open safe 
5. Someone might steal my shoes.
my shoes. might be stolen
6. What time can the boys hand in their papers?
what time can their papers be handed in