From this cross section of the grand canyon, what occurred between deposition and the formation of the precambrian metamorphic rocks of the lowest paleozoic rocks?

Number the steps from when a stimulus is received to when the body reacts

What is the approximate chemical composition of the solar nebula?

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.