How did imperialism, nationalism, and militarism contribute to making this a world war?

The holocaust of world war ii resulted in a) the nazis effectively used propaganda to gain and hold power in germany. b) ethnic regimes carried out mass devastation. c) deporting all european jews to the island of madagascar. d) the systematic mass slaughter of european jews and and others in nazi concentration camps during world war ii.

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

How and why did british north american colonists fight a revolution to create a constitutional republic, the united states of america?