These examples of different uses of the geographic perspective help explain why geographic study and research is important as we confront many 21st century challenges, including environmental pollution, poverty<span>, </span>hunger<span>, and </span>ethnic<span> or political </span>conflict.
<span>Because the study of geography is so broad, the discipline is typically divided into specialties. At the broadest level, geography is divided into </span>physical geography<span>, </span>human geography<span>, </span>geographic techniques<span>, and </span>regional geography<span>. </span>
<em>The relative age is determined by index fossils and the Darwinian theory of evolution. ... Only sedimentary strata contain fossils, so only sedimentary strata can be used to determine relative age determination</em>
One of the two main differences between the governmental structure of the Songhai kingdom and Ghana and Mali is that Songhai was divided into five provinces, while Ghana and Mali had strong central governments.
<span>armed conflict between the United States and the Soviet Union that led to the breakup of the Soviet Union the arrest of millions of people who opposed the Communist government</span>
