慢跑不只健身，还能健脑！
Many people find it hard to make themselves exercise. But a new study suggests that even a very slow run is good for the brain. It is the first study to show that slow running improves both mood and thinking.
Scientists at the University of Tsukuba tested 24 healthy young adults. Each person ran slowly on a machine for 10 minutes, at three to six kilometres an hour. Their heart rates were only 104 to 107 beats a minute. On another day, the same people sat still for ten minutes.
After the run, the people were in a better mood and felt more alert. They also answered faster and made fewer mistakes in a thinking test. On the day they sat still, however, they felt slow and sleepy, and they did worse in the same test. Special sensors (传感器) on the head showed that more blood with oxygen (氧气) was flowing to the front of the brain.
Why does slow running help? The scientists are not sure yet. Earlier studies found similar changes after faster running, so speed may not be the key. Those studies often used bikes because bikes made it easier to control the speed. But riding a bike does not move the head up and down very much. One idea is that this movement matters: when the head goes up and down again and again, it may make the brain work harder.
Slow running may also be important in human history. Long ago, people ran for hours to hunt animals. Scientists say running may be more than a sport — it may be a key part of how the human brain developed.
1.1. What is special about the study?
A It asked people to run fast.
B It asked people to sit still.
C It was done by 24 people.
D It is the first study to find this.
解析：选D。D 细节理解题。根据第一段的“It is the first study to show that slow running improves both mood and thinking.”可知，这项研究的特别之处在于它是首个发现“慢跑能改善情绪和思维”的研究。A说让人快跑，与原文“very slow run”相反；B说让人坐着不动，这是实验中的对照安排，不是这项研究最特别的地方；C说由24人完成，这只是实验人数，不能说明研究的特别之处。故选D。
2.2. How long did each person run on the machine?
A Five minutes.
B Ten minutes.
C Half an hour.
D Two hours.
解析：选B。B 细节理解题。根据第二段的“Each person ran slowly on a machine for 10 minutes...”可知，每个人在机器上慢跑的时间是10分钟。A“五分钟”、C“半小时”、D“两小时”在文中都没有依据，均与原文不符。故选B。
3.3. The underlined word “alert” in Paragraph 3 is closest in meaning to ______.
A quiet
B worried
C awake
D tired
解析：选C。C 词义猜测题。根据第三段的“After the run, the people were in a better mood and felt more alert. They also answered faster and made fewer mistakes...”以及后文“On the day they sat still, however, they felt slow and sleepy...”可知，跑完步后人们情绪更好、反应更快、错误更少，这与“slow and sleepy”形成对比，因此“alert”应理解为“清醒的、警觉的”，最接近awake。A“安静的”、B“担心的”与语境无关；D“疲倦的”与“sleepy”接近，正好与alert意思相反。故选C。
4.4. Why may running help the brain more than riding a bike?
A Running moves the head more.
B Running is easier to control.
C Bikes are used in old studies.
D Running makes the heart beat faster.
解析：选A。A 推理判断题。根据第四段的“Those studies often used bikes because bikes made it easier to control the speed. But riding a bike does not move the head up and down very much. One idea is that this movement matters...”可知，旧研究常用自行车是因为速度容易控制，但骑车时头部上下移动不多；而文章推测头部反复上下移动可能让大脑更努力工作。因此，跑步可能比骑车更有利于大脑，是因为跑步时头部移动更多。B“跑步更容易控制”与原文相反，原文说自行车更容易控制速度；C“旧研究使用自行车”只是事实，不是跑步更有助于大脑的原因；D“跑步让心跳更快”文中没有这样比较，而且慢跑时心率只有104到107次/分钟。故选A。
5.5. What is the best title for the passage?
A The Best Way to Keep Fit
B Slow Running and the Brain
C Bikes and Running: Which Is Better?
D How to Run Faster and Longer
解析：选B。B 主旨大意题。全文围绕一项关于“慢跑对大脑的好处”的研究展开，包括实验过程、实验结果、可能原因以及从人类历史角度的解释，因此最佳标题是“Slow Running and the Brain”。A“保持健康的最佳方式”范围过大，且文章重点不是一般健身；C“自行车和跑步：哪个更好？”只涉及第四段的一部分内容，不能概括全文；D“如何跑得更快更久”与文章主题相反，文章强调的是“慢跑”对大脑的作用。故选B。