The population of a country increases when higher than ​

Acontinental polar air mass foms in

Yo! a girl out ! i will give brainliest! hu one of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4