Why, since the ear of the earliest societies, have population centers sprung up in coastal regions and river valleys?

The primary agent of contact metamorphism is

Macbeth and lady macbeth are partners in the nurder of duncan and both become

Anight-club bouncer, now a top official,put coke or pepsi in it; first three initial. combine all lakes; but i still have more,of all the places; i have the largest shore.what am i? ?