Answer:
The indigenous peoples of the Americas arrived in North America via the Bering Strait land bridge, which existed approximately 15,000 years ago between Siberia and Alaska, and probably also via a succession of sea migrations from Asia.
Answer:
The presence in the air of one or more contaminants in such a concentration and of such duration as to cause a nuisance or to be injurious to human life, animal life or vegetation.
For much of the last quarter century, the leading theory of the driving force behind tectonic plate motions envisaged large scale convection currents in the upper mantle, which can be transmitted through the asthenosphere.
The answer would be B. Arable Land
Hard to answer when there is no map.