P waves is moved by compressing and expanding.
S waves is form perpendicular angle when they pass.
Here were the choices on that question:
a. poverty
b. lack of adequate rivers
c. mountains
<span>d. richness
The answer is D. richness. Based on A Companion to World History, the African Sahel can be a corridor of communication between Nile and Niger valleys but did not materialize. The reason was the richness of Sahel that it that it can provide for itself even without trade.
</span>
In the paleotmosphere, water vapor <span>was able to condense to form clouds and rain because the earth's surface cooled as there were fewer meteorite impacts.
answer=water vapour
hope this helps....</span>
Got this from google, scientists count a species population by first knowing the population in a certain area or small geographical sample location then multiply the result by the total area.
