Which element is not found in large quantities in earth’s mantle?
a. silicon
b. oxygen
c. iron
d. carbon

At a continent-continent convergence,

Nwhat way does renewable energy differ from nonrenewable energy?

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