What event in history has greatly affected the amount of greenhouse gases

Summary of the impact of the physical environment on settlement patterns and economic activities for ukraine

In which area will soil formation be greatest? a a steep slope in a warm,b wet climate a flat area in a warm,c wet climate a north-facing area on a steep slope a flat area in a cold, d wet climate description

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