2.) how does a hydrogen bond compared to a covalent bond?

just answered this

'A hydrogen bond is a strong form of a covalent bond. A covalent bond is one where two nonmetals share electrons. A hydrogen bond is where a hydrogen shares electrons with a very electronegative element, such as oxygen, nitrogen and fluoride.

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.