Mansa Musa was the famed emperor of A.Mali
The Great Wall stretches across North China from east to west for over 6,000 kilometers. It extends from the shanhai pass at the seaside in the Hebei province in the east to the Jiayu pass in Gansu province in the west.
Hello!
As you know, the Ring of Fire is a string of active and dormant volanic sites and seismic activity stretching from the Americas to Asia and down to Australia in the Pacific Ocean. This area has around 450 volcanoes (if not more) and is full of many trenches, which are deep and narrow excavations.
In this case the most likely cause of volanic activity in the area is best said to be b. The movemenet of mantle rock through the cracks between tectonic plates
These movements are also the same reason that explains the earthquakes that primarily occur in this region.
Hope this helps and if you need anymore clarifaction feel free to ask.
All i know is that Horace Mann made the educational system when he became Secretary of Education in Massachusetts in 1837, he set forth his vision for a system of professional teachers who would teach students an organized curriculum of basic content.