After he observed that south america and africa fit together like pieces of a puzzle, alfred wegener developed the theory of
a.
continental drift
b.
plate tectonics
c.
tectonic activity
d.
the layers of the earth

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.