Which of the following systems of trade was most widely used in ancient river civilizations? bartering

b
the exchange of coined money

c
free exchange

d
international trade
HURRY PLZ!!

Much of the ill will between armenians and the azeri people of azerbaijan arises because

What was piaget's explanation as to why preschool-age children in the preoperational stage make errors on tasks requiring conservation? a) preschool children's tendency toward centration prevents them from focusing on other relevant features of a situation b) preschool children have not yet developed numerical understanding; therefore, different amounts are meaningless c) preschool children's neural-visual network is not fully matured d) preschool children have not lived long enough and accrued enough experience to know the difference between quantities

Two ways government can build a good relationship with citizens?