How does the slope of the land affects the speed of lava flow

What is a compass? how does it work

If scientists only detect p waves in a certain layer of earths interior what does that tell us?

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.