Subsoil: This layer has normally less organic matter than the A horizon, so its colour is mainly derived from iron oxides. Iron oxides and clay minerals accumulate as a result of weathering. In a soil, where substances move down from the topsoil, this is the layer, where they accumulate.
Note: This information has been taken out of a website.
I believe the basement is the best answer
Hope this helps!
Answer:
<h3><em>w</em><em>h</em><em>a</em><em>t</em><em>'</em><em>s</em><em> </em><em>t</em><em>h</em><em>e</em><em> </em><em>q</em><em>u</em><em>e</em><em>s</em><em>t</em><em>i</em><em>o</em><em>n</em><em>?</em><em> </em><em>I</em><em> </em><em>t</em><em>h</em><em>i</em><em>n</em><em>k</em><em> </em><em>y</em><em>o</em><em>u</em><em> </em><em>n</em><em>e</em><em>e</em><em>d</em><em> </em><em>t</em><em>o</em></h3><h3><em>g</em><em>i</em><em>v</em><em>e</em><em> </em><em>m</em><em>e</em><em> </em><em>y</em><em>o</em><em>u</em><em>r</em><em> </em><em>q</em><em>u</em><em>e</em><em>s</em><em>t</em><em>i</em><em>o</em><em>n</em><em>s</em><em>.</em><em>.</em><em>.</em></h3>
Answer: They have larger ranges and thresholds.
Explanation: The rank-size rule defines range as the longest distance that a customer will travel to purchase a good or service. Threshold is the minimum market needed to support the supply of a product or service. It is assumed that customers which travel longer distances to purchase a higher-order good or service, and a provider of such goods and services will require a larger customer base to make a profit. Thus, higher-order services have larger ranges and thresholds.
Iran, Iraq, Saudi Arabia
These three countries fall in the desert area.