How did the byzantine empire to preserve and transmit classical greek and roman culture and knowledge?

under god i have placed my chiest strentgh and the safe guard to my loyal subjects

powers  are  denied  to the  national governmentin three distinct ways: some  powers, such as the  power  to levy duties on exports or prohibit the freedom of religion, speech, press, or assembly, are expressly  denied  to the  national government  in the  constitution.