Seven at one.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001525:Behavioral Sciences / Q000193:education*; D002648:Child; D004501:Education, Medical; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D013663:Teaching