One way in which the study of populations ( human populations - I assume) affects us is that they can help predict the population size in the future and prepare us for it. For example, if we see that the population is decreasing, a country might want to consider supporting child-bearing or immigration to avoid the problem of too many people receiving pensions but not paying taxes.
ANSWER: the ring of fire is a major area in the basin of the Pacific ocean where many earthquakes and volcanic eruptions occur.
They increased their sizes to rejuvenate the land. Before the war, everyone left their farms to go to the war. And once the war was over, the farms increased in size due to the high demand of resources needed to recover from the war.
