. Which of the following led to the start of the Crusades?

A
Constantinople was sacked by Muslims

B
Saladin seized the holy city of Mecca

C
Emperor Alexius I asked for aid against the Muslims

D
the plague devastated Europe and the Middle East

What was a major cause of world war i?

The quote below is an excerpt from the charter of the united nations: "the purposes of the united nations are: to maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace . " source:this section implies that the united nations is prepared to do what to keep world peace?

How did the united states ironically create a slaverybased market economy and democratic political system?