According to scientific thought, when does one species of organisms become two species?

a.
when one population becomes extinct

b.
when populations compete for the same resources

c.
when populations become separated from one another

d.
when one population cannot interbreed with the other population

The earth rotates on its axis and revolves around the sun every

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

Dry land planting can benefit the environment by reducing the need for tillagate