<span>Ore deposits of the element Aluminium do not require extreme concentrations because it is one of the most abundant elements in the earth's crust.
</span><span>Aluminium is the most common metal in the </span><span>Earth's crust.
</span>However aluminium can not be found free stand alone. All of the earth's aluminum<span> is combined with other elements to form compounds.</span>
23 countries in North America have a border with South America.
Explanation:
- It has an overland border with the continent of South America which runs along the Panama-Colombia state boundary. In total there are 23officially recognized sovereign states in North America.
- At some point, the boundary between North America and South America falls on Panama's Isthmus.
- The most famous demarcation in atlases and other documents parallels the dividing watershed of the Darién Mountains along the Colombia-Panama border where the isthmus meets the continent of South America.
<span>The four classes were the Brahmins (priestly people), the Kshatriyas (also called Rajanyas, who were rulers, administrators and warriors), the Vaishyas (artisans, merchants, tradesmen and farmers), and Shudras (labouring classes).</span>
The correct answer is B. An ecosystem resource; an ecosystem service
Explanation:
In ecosystems, a resource refers to any substance, material, object, etc. that is necessary for the biological processes of organisms, for example, breathing, growth, reproduction or nutrition. In this way, water is an example of an ecosystem resource because this natural resource is necessary for the life of almost all organisms. On the other hand, an ecosystem service refers to natural processes and systems that benefit humans, in the case of water cycle this is an example of an ecosystem service because due to this, humans get potable water to drink, water for growing plants and animals, among others.