Here were the choices on that question:
a. poverty
b. lack of adequate rivers
c. mountains
<span>d. richness
The answer is D. richness. Based on A Companion to World History, the African Sahel can be a corridor of communication between Nile and Niger valleys but did not materialize. The reason was the richness of Sahel that it that it can provide for itself even without trade.
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The answer is False because the Inuit people lived by hunting and fishing they lived in cold places where they could not farm
Explanation:
Both eras and periods are greater, but an era is more than 1 year
Answer:
a Doppler shifts in stellar spectra of nearby star.
Explanation:
Doppler effect it was discover centuries after Galileo and Kepler. It was proposed by the scientist Christian Andreas Doppler in 1840´s and around that years others scientist started to do some experiments to find the same effect.
Also Galileo could observe the moons of Jupiter thanks to a telescope that he built. At the begging, he thought it was some other stars near the planet. He named them as Medician planets, in honor to the Medici family because there were four.
Both Kepler and Galileo always made drawings of the sky, that means that any changes like parallax stars or the movement of an extrasolar system like meteorites.
Hope this info is useful.