Which country was actually divided by the Iron Curtain and how do you think that came to happen after World War 2​

The Iron Curtain specifically refers to the imaginary line dividing Europe between Soviet influence and Western influence, and symbolizes efforts by the Soviet Union to block itself and its satellite states from open contact with the West and non-Soviet-controlled areas.

the catholic church withhold people's access to the bible during the middle ages.

people could go to church and listen to the teachings, but it was absolutely forbidden to own and/or read the books of both the old and new testaments. it was also prohibited to translate the books (which where originally in biblical hebrew) to any other language.

this was done so the church could remain in control of what their teachings were and to enhance their importance and power, while also being able to judge people's actions through information that was unavailable for the general public.

food chain i would say only because there is competition on getting food and survival