What were the causes and effects of spread of islam

Why was the battle of gaugamela an important turning point in alexanders conquest of persians empire

How was the method of making pottery by using coils of clay better than simply shaping the clay by hand? it prevented pottery from cracking when fired. it created a watertight seal. it produced more attractive pottery. the pottery could be cut or stamped with designs.

What did roosevelt believe was a common cause of both bank runs and the great depression?