How did world war 1 affect the us economy after?

How did inovations in manufacturing lead to improvments in transportation?

How did the northern u. s. change during the 19th century? select the best choice from the answers provided. a. it became more industrial. b. it became more agrarian. c. it became less populated. d. it became less diverse

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?