Average IQ scores have increased steadily over the past 100 years. It has been argued that this effect is most likely due to an increase in the average number of years in school A a decrease in access to medical care, clean water, and nutritious food B an increase in population C a decrease in genetic mutations D an increase in genetic diversity

chronological thinking is an indispensable tool to structure a historical narrative and to give meaning to a sequence of events. the final section presents the results of a survey to test the chronological thinking of lower secondary school students carried out by the educational research institute.

answer; code of federal regulations;

answer; the intervening variable;