a type of brick that is made of clay mixed with straw and dried in the sun

 found in high mountains; also describes the mountain vegetation zone between the tree line and the snow line

 the division of land into zones based on elevation, which in turn helps determine climate and vegetation

the layer of air that surrounds the earth

 pattern of weather over a long period of time

a large area of Earth with a particular pattern of weather

 tree with needles and cones, such as a pine tree

 a large mass of ice found near Earth’s poles (continental ) or in a high, cold mountain valley (alpine )

_ natives of an area who have been conquered or dominated by others who came later

 lake that is large and deep enough for big ships

 raised area of land, such as a hill or mountain, with a flat top

the lowest elevation on mountains where snow remains year-round

moderate or mild, without extremes of hot or cold

_the creation of flat areas on mountain slopes for the purpose of farming

the highest elevation where trees grow on a mountain

the trading of crops between lowland and highland areas

What two factors explain why low elevations have denser air than high elevations? 

Brazil

Peru

Columbia

Venezuela

Argentina

Nicaragua

Chile

Bolivia