Words that express comparisons and relationships are some of the hardest concepts for young children to grasp

The procedure known as trephining involved

a. brain surgery to remove the pineal gland. b. an early form of electroconvulsive shock. c. forcing the patient to abstain from food and drink for long periods of time. d. drilling a hole in the skull of a person to let out demonic spirits. e. the drinking of foul-tasting concoctions.

Don tells Ray he wants to get a new sports car. Ray immediately understands why, because he is familiar with the common characteristics of sports cars and knows what makes them different from family cars. Ray is using mental categories called _____

a) classes. b) concepts. c) attributes. d) classifications.