Which best describes the demographics of Europe? OA. Low birthrate and positive migration rate

O B. High birthrate and negative migration r

OC. Low birthrate and negative migration rate

OD. High birthrate and positive migration rate

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.