Human beings spread all around the world over a period of millions of years. Identify when humans arrived in different regions of the world. 200,000 years ago, 100,000years ago, 40,000years
ago, 30,000years
ago

What was on result of the potato famine

Plzz on what physical process is responsible for the creation of volcanoes, earthquakes and ocean trenches at the plate margins?

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