They are considered guesses because they were never proven to be correct. They're a idea on a certain subject that can't be proven true for example the big bang theory that our universe was created from a explosion cannot be proven true because no one really knows how its created.
A state park since it’s owned by the state and not anyone else because a single-family residence is private and you can only go there is you live there, a mine is obviously private because you gotta work there, and a factory is also private because it’s owned by a company and not aloud to the public.
