Marwan understands that when a ball of clay is flattened into a pancake shape that there's still the same amount of clay. He says, "you could just bunch up the clay into a ball again—it's still the same thing." He is exhibiting:

Which of the following will likely contribute to the pervasiveness of emerging adulthood in developing countries?

a. participation in tertiary education. b. increase in population. c. adults living longer and healthier. d. marrying for love and not by arrangement.

How long are candidates for sex-change operations usually required to live in the community as a member of the opposite sex?

a) 1 or 2 weeks b) 1 or 2 months c) 1 or 2 years d) 10 to 12 years