What term defined a well tested , scientifically supported statement the explains how something works

What triggered the surge of conservative governments in central europe at the end of world war i? a. the disintegration of european families in the wake of urbanization. b. a worldwide revolutionary upsurge. c. the revival of the austrian-hungarian and ottoman empires. d. the british suppression of the indian nationalist movement. e. the killing of the tsar during the russian revolution?

How did justinian attempt to revive the “glory of rome”?

He table below shows the number of immigrants to the united states from different regions of europe between 1871 and 1910