Which development encouraged Arab traders to exchange goods for slaves in sub-Saharan Africa in the 11th and 12th centuries?

Answer    well it was money, power and land

Explanation:

 They are arab

for starters, there is the structural trend of rising primary government expenditure as a share of gdp, which reached 36% in 2014, up from 22% in 1991. this increase reflected a political desire to address the poverty and inequality that had gone unaddressed during previous decades. to support the increase, brazil’s government increased taxes on consumption and promoted progress toward labor-market formalization. nonetheless, public investment, particularly in infrastructure, took a hit. in fact, with the exception of the 2005-2008 period, total investment as a share of gdp has remained below 20% since 1991.

d) he bring down boss tweed and tammany hall.