Answer:
Agriculture allowed people to stay in one place, and increased food production caused the population density to expand far beyond levels that could be sustained by hunting and gathering alone. This growth in population density provided a critical mass of people to sustain and spread contagious infectious diseases.
Answer:
Option (4)
Explanation:
Seismic P and S waves are generated during an earthquake that has the potential to propagate through the interior of the earth. P waves are also known as the primary waves and they move in a compression and extension way in their direction of propagation. S waves are shear waves. This P waves travel faster than the S waves and can travel in both solid as well as in liquid. Whereas the S wave can travel only through solids. They get absorbed when they reach the core-mantle boundary. These two waves are helpful in determining the epicenter of an earthquake by recording the arrival of these waves.
Hence, the correct answer is option (4).
I think the answer is A.
But correct me if I’m wrong
I hope this helps :)