What could be the specific resonance for studying physical geography?
a. to us prepare for quick changes like the weather.
b. to us prepare for dangerous people entering our country.
c. to us prepare for going outside.
d. to prepare for climbing a mountain.

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks