Which factor led to the rise of communist revolutions in russia and in china?

Space is not completely empty. there are small particles in space. what happens when these particles come together?

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.

Which statement in the passage best reflects sumer's opinion of the dred scott decision? a."i speak what cannot be denied." b."[the] judgment was sustained by a falsification of history." b."the opinion was more thoroughly abominable than anything history." i speak what cannot be denied when i declare that the opinion of the chief justice in the case of dred scott was more thoroughly abominable than anything of the kind in the history of courts. judicial baseness reached its lowest point on that occasion. you have not forgotten that terrible decision where a most unrighteous judgment was sustained by a falsification of history. -charles sumner, 1865