The presidents salary and expense allowance equal:
a. $250,00
c. $400,000
b. $300,000
d. $450,000

where is the

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.