What causes the aurora borealis or northern lights to occur?

-streams of charged particles from the sun mix with earth's atmosphere
-light from the moon reflects on earth's atmosphere
-charged particles from the sun reflect off of the ice at the poles
-none of the above

What is a reasonable action that provides safe water for communities?

According to the theory of continental drift, what was the priginal state of the worlds continents

Which of the following would not be considered a geographic impact on the history of middle and south america? a. the relative geographic isolation of the americas meant that they would be more susceptible to european diseases. b. ernesto “che” guevara's trip throughout south america inspired him to become a revolutionary. c. the tropical climate of north america has encouraged many south american countries to produce goods there. d. the proximity of the united states to middle and south america has strengthened its relationship to the region.