单项选择题


Questions 14 to 16 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
Now listen to the passage.
The best statement of the main idea of this passage is that

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.