There are 3 theories about how the Mayan empire declined. Name 2 of the theories.

What term is given to the border between the central alps and the southern limestone alps?

The hebrews originally migrated from a. india b. egypt c. arabia d. mesopotamia

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.