What were some causes and effects of immigration patterns and policies from 1900-1945

Which impact did the civil war have on the spread of disease in texas a. disease decreased bc people left the area to fight in the war b. disease increased bc medicine was in short supply. c. disease increased bc many new diseases were brought to the area d. disease decreased bc confederate doctors distribute new medicines to local communities

During the era of european expansion, what was the biggest reason for spain’s push for exploration?

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?