Why were state constitutions significant when the united states constitution was written?

The system of checks and balances ensures that

Which character are always present in all living organisms

Two of these describe "federalism." (choose two answers) select one or more: a. the national government absolutely controls all state governments. b. power is shared by the national and state governments. c. state governments exercise absolute power over the national government. d. it is a compromise meant to eliminate the disadvantages of a "unitary" and a "confederate" system.