Why did the us declare war against mexico?

Which of the following are ways that people in democracies can take part in politics and gonverments

Me asap worth brainlieist and 50 points

Which phrase correctly completes the statement? "the korean war " lasted 3 years. has never ended. was won by north korea. was won by south korea lasted 3 years. has never ended. was won by north korea. was won by south korea.