What was the most important effect of the Panama Canal on trade? It increased tariffs on Latin American goods being sold in the United States.

It decreased the amount of time needed for ships to travel from the Atlantic to the Pacific Ocean.

It created economic disputes that ultimately led to the Spanish-American War.

It ended illegal trade between the United States and Latin American countries.
What has been a long-term effect of the Panama Canal?

It has largely decreased the US military presence in Latin America.
It has greatly improved the amount of fertile farmland in nearby areas.
It has become one of the most important trade routes in the world.
It has quickened the spread of diseases like malaria and yellow fever.

Dr. laguardia is a cognitive neuroscientist who is interested in the effect of brain concussions on the ability to recognize faces. he conducts a quasi-experimental study in which he examines football players before and after the regular season using the benton facial recognition test (a published, widely used measure of one's ability to recognize faces) to compare those who received concussions to those who did not. he finds that players who had concussions during the regular season performed worse on the benton facial recognition test than did players who did not experience which of the following is true regarding external validity in dr.laguardia's study? a. because dr. laguardia selected participants who actually experienced concussions, the study b. because dr. laguardia's study is a quasi-experiment, it is impossible to obtain c. because dr. laguardia's dependent variable was assessed in the laboratory, the study 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.