Question 9 greatly restrict(s) economic development in Sub-Saharan Africa.
lack of land for industry
rugged coastlines
poorly developed infrastructure
shortages of workers

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.