How was the authority of the central government established

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus

Which 19th century technological advancement would best allow farmers along the mississippi river in iowa to quickly transport their crops to buyers in louisiana?

What was the primary purpose of the sibley commission in georgia? to schools across georgia integrate peacefully to discover how georgians felt about the issue of integration to lead non-violent protests to elect new civil rights leaders