Most Early River Valley civilizations (3000 B. C. - on) had economies that changed over time. Which line best explains how most Early River Valley economies changed?
A.
command → traditional → market
B.
traditional → command → market
C.
market → command → traditional
D.
market → traditional → command

What evidence does the writer give to support his argument about coral reefs? a) he speaks of the activities of coral polyps. b) he describes the composition of the great barrier reef. c) he emphasizes the ways in which coral reefs are fragile. d) he points out the ways that scientists do research on the reefs.

Astate's representation in the u.s. senate is based on a) equal representation. b) the state's population. c) the state's electoral votes. d) the size of their major cities.this independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren cthis independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren commission (wc) b) federal election commission (fec) c) equal opportunity commission (eoc) d) securities and exchange commission (sec)

In plate tectonics, why is the north american plate tectonically inactive?