题目内容：
1. What makes the brain better able to process information?A) Vigorous physical exercise. B) Skill-based exercise.
C) Both of them. D) Neither of them.
2. While _______ of rats showed a greater number of brain connections, _______ had a greater density of blood vessels in the brain.
A) the first group / the third group B) the second group / the third group
C) the first group / the second group D) the second group / the first group
3. One possible reason for scientists to make experiments with rats or other animals is that _________.
A) rats benefit from the experiments
B) the experiments can boost the brains of the rats
C) an effect found in rats may also apply to humans
D) rats and humans are very much alike
4. Which word in Paragraph 6 tells us that older adults were divided into groups in the human studies?
A) Corresponding. B) Inactive. C) Older. D) Faster.
5. Which of the following is not a finding that results from the studies of older adults?
A) Regular exercise can improve the speed with which the brain processes information.
B) Inactive adults can hit buttons faster in response to a tone after being trained.
C) Getting old is the cause for the reduction in mental function.
D) Exercise can make one smarter.
参考答案：