Answer:
<h3>Migration can be defined as “a process of moving, either across an interna- tional border, or within a State. ... The phenomenon of migration has been indispensable to human histories, cultures, and civilizations</h3>
There is no set number of "lines" of longitude. You're free
to draw as few or as many 'lines' to mark the 360 degrees
of longitude on the Earth's surface.
However many lines you decide to draw on your map or globe,
they ALL cross the equator.
<span> another name for the great plains is the Great American Desert</span>
