What is the surface layer of the earth on which vegetation grows

The map above shows where people live in the united states. areas that are darker blue are areas where people live close together. areas that are lighter colors are places where people live farther apart. as a geographer, if you were to study where people live and why they choose to live in these places, which of the six essential elements of geography would you be using?

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

One disadvantage that darwin faces today is w. enemy attacks x. natural disasters y. lack of land bridge z. high population density