Since the continental crust density is the same, when both of them collide, there will gradually occur a huge mountain chain cause of the uplifting of the collision point and it's surrounding area, today known as the Himalayan mountains, the highest in the world (note: if measured from sea level) with it's peak Mount Everest (Sagarmatha) at 8848 m above sea level (it is estimated that it grows 8 cm per year).
The crust is the part you walk on, and it's the surface of the earth.
I think it would be "A) Oil below Earth's surface absorbs precious water supplies." but I'm not positive
There is terrorism, slavery,hunger, an disease and much more.
The biggest reason why ancient Greece never chose a single King, and was dominated by smaller city-states instead, are the geographic features of the land where these cities were settled. The mountainous terrain, the isolation of the valleys, and the number of isolated islands would make it difficult for one person to govern it all.
Also, Greeks were famous for their aristocracy that prevented the forming of monarchies. Political independence of the city-states was constantly protected by the aristocracy and so, any individual who would want to conquer the territory would succeed for only a short time and would never have the glory and respect of a real king.