Congress did not have the power to C. Collect taxes.
due to the destruction of infacturature and capabilities, lacked the ability to communicate with each other and coordinate a response.
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
