"what is significant about the yearly flooding of the nile valley?
the floods typically killed many people, making it hard to live in the valley; most people moved to the mountains above the riverbed.
it is the only geographic disadvantage of the area.
it replenished the nutrients in the soil, making the valley very fertile.
it prompted the egyptians to build enormous pyramids to escape the floodwaters."

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?