One reason why groups of Native American Indians often developed different cultures was
that each group

Adapted to it's environment in a different way.

Explanation:

The development of human culture is linked to the geographical environment in which they live. This evolutionary aspect allows the human race to adapt to different environments over time and around the world.

The geography in North America is very diverse; from the great plains to swampy areas, and great mountains, they allowed very diverse cultures to develop throughout America.  

These cultures are different because they adapted to their environment, and also because of the geographical separation in which they developed.

I hope this information can help you.

i think it is the byzantine empire

well that depends on how deep the hole is. you'd first go through te crust of the earth, then the upper mantle, then the lower mantle then the outer core, then the inner cor then you'd be stuck in the core to melt.