Which of these must be present for international trade to be successful? a system for securing borders
a system for raising taxes
a system for imposing protective tariffs
a system for exchanging currencies

Which options most accurately assess the impact of transportation improvements (e. g., railroads, canals, steamboats, transcontinental railroad) on the settlement of the west? ***(select all that apply.)*** a. they led to an increase in population density. b. they made it easier to travel long distances. c. they in establishing towns. d. they led to the development of the fur trade. e. they allowed for international travel.