What best explains the demise of city patronage systems in the early twentieth century?

1: how did the rise of rulers with total power in europe and asia lead to world war 2?

Which four of these developments were made under mongol rule during the pax mongolica? the extension of the grand canal in china the spread of christianity the spread of weapons that used gun powder the invention of new medicines the establishment of a postal system the invention of geometric models of lunar motion

Which was not characteristic of rome's two-hundred-year pax romana? oppression independence stability peace