Doctors chase and sanborn are conducting an experiment on the effects of caffeine on memory. participants are randomly assigned to a caffeine or a no-caffeine group; their recall of items on a word list is later assessed. which pair correctly identifies a variable in this experiment?

The development of simple stone tools by early hominids led to the ability to procure meat more efficiently. this in turn led to the change in diet that included larger amounts of protein. many scholars believe that this shift in diet was a significant part of how our ancient ancestors adapted so quickly to a varied set of environments, and thus were able to begin cultural development. this demonstrates the intimate connection between