In the story of Oedipus he was given a prophecy saying that he would kill his father and marry his mother. And in the end of the story he does end up killing his father and marrying his mother. This is foreshadowing, a clue or event that has happened before that tells of an event that will happen in the future.
B. The region was rich source of farmland.
the British colonidt wanted farmland so they could make money
The Monroe doctrine was a warning to European countries that the US would not tolerate any more colonization fo any land in the Western Hemisphere by European states and wanted them out. It was written as address to Congress, but meant to be a passive aggressive statement to European imperialist nations.