A．human brains differ considerably
B．the brain a person is born with is important in determining his intelligence
C．environment is crucial in determining a person's intelligence
D．persons having identical brains will have roughly the same intelligence
A．individuals with identical brains seldom test at the same level
B．an individual's intelligence is determined only by his environment
C．lack of opportunity blocks the growth of intelligence
D．changes of environment produce changes in the structure of the brain
A．can be predicted at birth
B．stays the same throughout his life
C．can be increased by education
D．is determined by his childhood