. What is the main difference between the outer core and the inner core of the Earth? The inner core is mostly solid iron, the outer core is mostly liquid nickel. The inner core is solid iron and nickel and the outer core is liquid iron and nickel. The inner core is cooler because it's solid and the outer core is hotter and liquid. The inner core is hotter and liquid and the outer core is cooler and solid.

A) The inner core is mostly solid iron, the outer core is mostly liquid nickel

Explanation:

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.

atp is used for energy.