Hart and Risley$$s study of language development showed that Question $73$ options: $1)$ Only the quality of words and not the quantity of words children hear is most important in language development $2)$ Children of lower SES families heard fewer words than children of higher SES families $3)$ Children of lower SES families hear more conversational talk than children of higher SES families $4)$ Language measures at age $3$ did not predict academic success at age $10$