2) when did germans vote on annexing austria? when did german troops move into austria?

answer; i believe that the correct answer to the above question is; (tariff)

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.