The challenge of aging.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D001290:Attitude; D005260:Female; D006309:Hearing; D006801:Humans; D007223:Infant; D007360:Intelligence; D008297:Male; D008606:Mental Processes; D008875:Middle Aged; D014825:Vocabulary