As early humans moved into river valleys, what were some of the contributing factors that contributed to epidemics? (check all that apply)

the right choice would be a. culture within the city-state. c. loyalty to the police. d separation by land and sea.

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.