Compare the emergence of advanced civilizations in Meso and South America with the four early river valley civilizations. Which of the following systems of trade was most widely used in both ancient river civilizations and ancient Native American civilizations?

bartering
the exchange of coined money
free exchange
international trade

the answer to your question is ( syngman rhee) have a great day

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

george kidding

written by alan ward and published in 2003. ward is a historian and was a professor at the university of connecticut.

if this isn't what you are looking i would like to know more details.