Answer:
What do you mean by that?
Explanation:
From lakes and grasslands with hippos and giraffes to a vast desert, North Africa's sudden geographical transformation 5,000 years ago was one of the planet's most dramatic climate shifts.
The transformation took place nearly simultaneously across the continent's northern half, a new study finds. The results will appear in an upcoming issue of the journal Earth and Planetary Science Letters.
http://www.livescience.com/28493-when-sahara-desert-formed.html
The answer is B) by John C Calhoun giving in to Andrew Jackson.
He was trying to find a water route west to Asia, but instead he found the Americas.
Answer:
The fall of the Roman Empire.
Explanation: