South korea created two free trade zones in the 1970's and added several more since 2000. how is international trade in those zones today different from international trade prior to 1970?

How did inca develop their road system? a) they used mortar to hold the stones together. b) they built suspension bridges over rivers. c) they mixed copper and stone together to make the blocks. d) they laid roads in the cities, not in the less densely populated deserts.