Which of the following countries has a life expectancy that is less than 50 years? a. singapore b. south korea c. argentina d. iraq e. malawi

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.