The pentagon papers
a. were not a political problem for nixon or any of his cabinet
b. were a secret study of the history of u. s. involvement in vietnam
c. were leaked to the new york times by robert mcnamara
d. were prohibited from being published in a decision by the supreme court

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration

hmm.. that's be opened free elementary school for young boys who showed artistic potential. closed rome to outsiders to protect its unique style and methods of producing art. and employed scribes to copy latin and greek texts.

the increased economic and military power of the sumerians can be attributed to the 2 rivers namely tigris and euphrates. these rivers the sumerians in growing their crops to which they could sell. the 2 rivers also made a good defense mechanism for the sumerians.