Ponerle los nombres a TODOS los límites (ríos, arroyos, cuchillas, laguna, límites artificiales y contestados)

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years

Answerstratovolcanoes///near or in the ring of fire;

Bcold,less-dense air falls