quickly selected Thus, geologists and engineers Thus, geologist and engineers could immediately begin
conducting tests, collecting data, and mapping the dry riverbed. Meanwhile, to the
surprise of officials, stopping the flow of water did not stop the flow of tourists. There
had never been a chance to see Niagara Falls without water before. The
______was unique.

A: opportunity
B: reflection
C: entrance
D: design

This is from the DRP