Earth can be divided into four major spheres: the hydrosphere, the atmosphere, the and the biosphere. 4. earths lower mantle lies below the __5. a __ is a group of interacting parts that form a complex whole.

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