Does anyone know how to explain on how movement is important? I really don't understand this assignment..

Which type of seismic waves are confined at the surface

What are economic benefits of building dams

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.