Look at the map
The purple region was colonized by
The green region was colonized by

The impact of a large asteroid comet with earth has been proposed to have caused the extinction of the dinosaurs. the impact site of this comet is in or near

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.

Which of the following is the main purpose of using an anchored network of booms which funnel debris to a collection area?