1.People think the creature walks a gorilla.
The creature is thought to walk a gorilla
2.They think the government found a UFO.
The government is thought to have found a UFO
3.Experts believe that he didn't see a ghost.
He is believed not to have seen a ghost
4.They report that natives have spotted Bigfoot.
It is reported that natives to have spotted Bigfoot
5.People say the Loch Ness Monster exists.
The Loch Ness Monster is said to exist