What was public sanitaition like in the middle ages?

How did the phillips brothers expand their businesses? by selling it to other businessmen by changing their source product by merging their companies by acquiring government support

Who was in charge of american troops during 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?