What are the merits and drawbacks of american federalism?

The federalist arrangement has advantages and disadvantages.

The great advantage of a federal system, or at least with subnational divisions of government, is that the agreements between rulers and governed can be given in a more localized way and with a direct link to the extent that the authorities are closer to the citizens

Its great disadvantage, however, is that the coordination of different areas of government as well as the multiplicity of jurisdictions can lead to coordination problems that detract from government action. In some ways, the advantage of federalism is representative, its main disadvantage is organizational in terms of the effectiveness to carry out large-scale joint tasks.

The value of federalism is that it increases and facilitates opportunities for citizen participation in the definition of what the public problems of the community are and what their treatment should be. It also increases opportunities to collaborate with the government in policy development, to monitor public administration and to evaluate its results.

answer; when one group has an extremely high score at pretest;

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.