Which of these energy resources might replace dwindling petroleum supplies one day?

In the developed world, describe the changing role of women in agriculture.

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.

Largest layer of atmosphere international space station orbits ultraviolet radiation causes ionization the phrases describe what layer of earth's atmosphere?