The Gusii people of Kenya do not speak with their children directly, but it is clear that their children reach the same language milestones as American children. It has been demonstrated that Gusii children learn language from .

Martha participates in a research study in order to receive extra credit for her psychology class. when she arrives in the research office she is given a can of what looks and tastes like beer, but which actually contains no alcohol. in the adjoining room martha's classmate karen is also participating in the study. karen receives a can of alcoholic beer. if the experiment was designed to test the effects of alcohol on concentration, then who is exposed to the independent variable?