They mostly had resources , and locations in common.
The country's inability to supply enough food or jobs for its rapidly growing population.
the sun/radiation (sorta)/ fusion/(yea pretty much the sun)
The Grand Canyon is like a history book because you can see all the layers of rock and dirt throughout the ages, and scientists can read those to tell what happened.
Hope this helped :)
The correct answer is - Watershed.
The drainage basis are places in which all the water in an area is accumulated and ends up in the same place. The drainage systems are divided by highlands, which can vary from small hills to very high mountains, depending on the topography of the place.
The line on the highland that is separating the drainage systems is called watershed. The watershed is simply a line stretching on the highest parts of a highland, thus having a slope on each side.
