The most productive farmland in the region is asia minor anatolia dasht-e kavir fertile crescent

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

The chemical or mechanical process by which rock is gradually broken down eventually becoming soil