A federal system is a system of government where power is

Federalism is the system of government in which power is divided between a central government and regional governments

Explanation:

answer; i believe its jutland peninsula and scandinavian peninsula;

answer:

d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.

the widely used measure that he applied to his experiment was the benton facial recognition test. it employed on to football players and as result, only players who suffered brain concussions did not pas this test. and although it has an external validity, it is limited because it isn't general to apply to other population.