Why do you think sand is constantly changing shape

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

Which layer surrounds the center of the earth? a: crust b: core c: mantle

Migrant workers who fill employment needs in their host country often send remittances to their home countries