Ascientist wishes to learn about volcanoes and earthquakes. which of the following spheres should she most directly study? a. atmosphere b. biosphere c. cryosphere d. geosphere

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.