Which statement about secondary sources is true?

What role did the catholic church play in the development of the heliocentric theory promoted by copernicus and galileo?

Marx and engels believed that a communist revolution would defeat capitalism and that the revolution would be led by

Following archduke franz ferdinand's assassination, austro-hungarian leaders: a. aided the ottoman empire in its campaign to keep serbia under its control. b. executed nearly all prominent serbs living in austria-hungary c. threatened to invade serbia if serb leaders did not agree to a set of strict demands. d.. formed an alliance with great britain to protect austria-hungary from future attacks.