When boys are in puberty, they typically do not know that they have begun to produce sperm until they experience?

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.

the money supply is the total amount of money available in the economy. how do changes in the money supply affect people and businesses?