How might the families of astronauts be affected by their choice of career?

How does the parallax of a nearby object compare to that of an object farther away?

The primary agent of contact metamorphism is

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.