Use of the term iron curtain is meant to symbolize and highlight differences in

1. religious philosophy
2. political ideology
3. art and architecture
4. resources and climate

  2. Political ideology

Explanation:  Iron Curtain is a term coined by Winston Churchill, and refers to the pronounced political and ideological differences between the West and the East during the Cold War. These political differences were between the democratic West, and the communist East to which Communism was imposed by the Soviet Union. The policy difference was manifested by constant tension, arms race, geo-strategic influences, etc.

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

b.lincoln had the victory he wanted for emancipation