While discussing a new short story about living in the Arctic with a student, a teacher discovers the student is struggling to comprehend the text even though she has previously been capable of comprehending other grade-level texts with little struggle. What is the student likely missing in order to be able to fully comprehend the text

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?