А. The six ravens (to keep) in the Tower of London now for centuries. They used to come in from Essex for food cracks when the Tower (to use) as a palace.
Over the years people (to think) that if the ravens ever left the Tower, the monarchy would fall. So Charles II (to decree) that six ravens should always (to keep) in the Tower and should (to pay) a wage from the treasury. Sometimes they (to live) as long as 25 years but their wings (to clip) so they can’t fly away, and when a raven (to die), another raven (to bring) from Essex.
Active or passive!!!