Whats the difference between subduction and accretion

Which revolution led to the development of these civilizations?

What benefits does this type of farming have?

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.