What is the money that people earn for Their labor called? two answers
Duties
Income
Price
Fees
Taxes
Wages

vertical merger is the term used for the joining of two or more firms involved in different stages of producing the same good or services.

explanation:

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.