What was the eisenhower doctrine? the united states would immediately try to liberate all of the countries behind the iron curtain. the united states would use force to middle eastern nations threatened by communism. the united states would nationalize the suez canal. the united states would recognize the peoples republic of china?

B - the united states would use force to help any Middle Eastern nation threatened by communism.  

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2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

in mcculloch v. maryland (1819) the supreme court ruled that congress had implied powers under the necessary and proper clause of article i, section 8 of the constitution to create the second bank of the united states and that the state of maryland lacked the power to tax the bank.

gibbons v. ogden, (1824), was a landmark decision in which the supreme court of the united states held that the power to regulate interstate commerce, granted to congress by the commerce clause of the united states constitution, encompassed the power to regulate navigation.