The Cold War lasted 40 year stand between USA and Solvate Union. USA at the time was a capitalist country 1st world nation and USSR is a communist country a 2nd world nation.
USA had lots of nuclear power and started making all of these bombs so then the Soviet Union decided to make bombs to. It got up to the point that if they dropped the bombs their world be no living life for a long time sot they decided to no fight because they wanted life on earth.
The life expectancy of first world nations is high because they have hospitals, medicine, and a better living environment. Third world nations don't have the medical supplies as first and second world nations do. It also has something to do with health and hygiene because if their living environment. Health is key in major populated countries because people live in unsanitary homes and streets.
The US send these things to a third world nation is because they do not have a lot of these things and we also get a lot of items from third world nations because they make most of the things we use everyday.
Transportation systems are plains, trains, boats, cars, and by horse. Plains, trains, boats, and cars are mostly used in first and second world and third world has cars, plains, trains, and boats but they are not as nice and new as first world nations. The cars are like see a portal into the past because they are from the 60s and 50s which still work.
Education in most countries are poor and they don't have new classrooms to learn in they just only go to school till 5-14 years old and then they could go to high school. In the USA we have preschool though collage education with trained teachers to teach us the things we are expected to learn.