Which statement describes a positive effect of a drought in a savanna ecosystem? a) The leaves of the grasses dry up without enough water.
b) Dried leaves catch fire and cause wildfires.
c) Animals that eat leaves die from lack of food and water.
d) The decaying remains of organisms add nutrients to the soil.

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