Contacts between sedentary and nomad peoples<span> resulted in trade, tribute payments</span>
Answer:
Wind exists because of differences in air pressure. (Meteorologists call the force that pushes air horizontally between high and low pressure regions the "pressure gradient force.") The resulting rush of air between these two locations is the wind we experience.
Tourism is the LARGEST industry in the world.
A tributary is a source of water for creeks and is one of the few starts of the water system. It would be d