Hi please tell me which one is wrong

Stories that are passed down through generations by word of mouth are called

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?

Why do you think that historians use the word “revolution” to describe important changes in agriculture? how did the green revolution and other agricultural revolutions change the lives of billions of people? < < read less