Answer:
A. The population is divided among four major ethnic groups.
D. ethnic and tribal conflict has been central to Afghan history.
Explanation:
Afghanistan is an Asian country with four major tribes which are Pashtun, Tajik, Hazara, Uzbek. When the Pashtun tribe which requires called the Talibans occupied the seat of power they began to oppress other tribes.
They began denying the other ethnic groups basic amenities and also started killing other tribes. This was due to ethnic and tribal conflict being central to Afghan history.
This cruel behavior led to an interference from Human right watch which eventually led to the removal of the Pashtun in power.
Only one president, <u><em>Woodrow Wilson</em></u>, had a doctorate, and was president of Princeton University before becoming the U.S. President.
The main mechanism through which the layering happened is gravity: it pulled the heavier, denser material to the center, leaving the less dense material on the surface.
The material that was on the outside cooled quicker, but this was the result, not the cause.
The answer is
<span>2) Gravity caused more-dense material to move toward the center of each planet.</span>
