What do you understand by gm crops? agriculture

How does central place theory explain patterns in the size and distribution of cities?

Acivilization exists for several hundred yeaars, developing its own language. such a civilization probably has been: a. farming corn b. suffering from a lack of contact with the outside world. c. isolated by mountains or some other physical barriers. d. starving from lack of trade.

Uncle tom's cabin started out as a series of articles printed in the national era, a newspaper.