The lord would provide to the vassal land from which they could make money from and in return the vassal would contribute troops to the lords army. Sometimes vassals would also pay a small fee of grain or various other goods as a sort of tax for the land.
World War I, which lasted through Jul 28, 1914 to Nov 11, 1918.
https://www.history.com/topics/world-war-i/world-war-i-history
Info at the link
The Constitution mandates that Congress convene at noon on January 3, unless the preceding Congress by law designated a different day. P.L. 113-201 set January 6, 2015, as the convening date of the 114th Congress.
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The population is younger when life expectancy are shortened.
The population decreases from low birth rates and high death rate.
The diseases continue when cycles of infection occur.
The productivity declines when people are too sick to work.
Explanation:
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