Explain the statement, "the amazing mechanization of agriculture in the postwar years was almost as striking as the mechanization of industry."

This related to the civil war

Explanation:

The Civil War was the first modern war which had been the first time technology and industrial strength played a significant role. The technology invented was supremely beneficial agriculturally but not as much so as factories [The farm becomes a factory]

When there is scarcity and choice there is/are .

b. costs.  

Explanation:

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.