真题来源
2024年6月大学英语四级考试真题（节选）
 
真题原文
Passage 12: The Impact of Physical Exercise on Brain Health
Physical exercise is widely recognized for its benefits to physical health, but recent research has shown that it also plays a crucial role in maintaining brain health. Studies have found that regular physical activity can improve cognitive function, enhance memory, and reduce the risk of neurodegenerative diseases such as Alzheimer's and Parkinson's.
One of the key ways in which exercise benefits the brain is by increasing blood flow and oxygen supply to the brain. When we exercise, our heart rate increases, pumping more blood to the brain. This increased blood flow delivers essential nutrients and oxygen, which are vital for brain function. Additionally, exercise stimulates the production of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and survival of neurons. Higher levels of BDNF have been linked to improved learning and memory.
Moreover, physical exercise has been shown to reduce inflammation and oxidative stress in the brain. Chronic inflammation and oxidative stress are major contributors to cognitive decline and neurodegenerative diseases. By reducing these factors, exercise helps to protect the brain from damage and maintain its structural integrity.
Another important benefit of exercise is its impact on mental health. Regular physical activity has been shown to reduce symptoms of depression and anxiety by releasing endorphins, the body's natural feel-good chemicals. This not only improves mood but also enhances overall well-being.
Despite these benefits, many people still do not engage in regular physical exercise. One major barrier is the lack of time due to busy schedules. Another is the perception that exercise must be intense or time-consuming to be effective. However, research has shown that even moderate levels of exercise, such as brisk walking or cycling, can have significant benefits for brain health.
To encourage more people to incorporate exercise into their daily routines, public health initiatives are promoting the idea of "active living." This includes creating environments that support physical activity, such as building walking trails and bike lanes, and encouraging activities like taking the stairs instead of the elevator. By making small changes in daily habits, individuals can significantly improve their brain health and overall well-being.
In conclusion, physical exercise is not only important for physical health but also crucial for maintaining brain health. By increasing blood flow to the brain, reducing inflammation, and improving mental health, exercise offers a powerful way to enhance cognitive function and protect against neurodegenerative diseases.
 
翻译
第十二篇：体育锻炼对大脑健康的影响
体育锻炼因其对身体健康的益处而被广泛认可，但最近的研究表明，它在维持大脑健康方面也发挥着关键作用。研究表明，定期进行体育活动可以改善认知功能、增强记忆力，并降低患阿尔茨海默病和帕金森病等神经退行性疾病的风险。
锻炼对大脑的一个关键益处是增加大脑的血流和氧气供应。当我们锻炼时，心率加快，向大脑输送更多的血液。这种增加的血流输送了对大脑功能至关重要的营养物质和氧气。此外，锻炼刺激大脑源性神经营养因子（BDNF）的产生，这是一种支持神经元生长和存活的蛋白质。高水平的BDNF与改善学习和记忆能力有关。
此外，体育锻炼已被证明可以减少大脑中的炎症和氧化应激。慢性炎症和氧化应激是认知能力下降和神经退行性疾病的主要原因。通过减少这些因素，锻炼有助于保护大脑免受损伤，并维持其结构完整性。
锻炼的另一个重要益处是其对心理健康的影响。定期进行体育活动已被证明可以通过释放内啡肽（身体的天然快乐化学物质）来减少抑郁和焦虑的症状。这不仅改善了情绪，还增强了整体福祉。
尽管有这些益处，许多人仍然不进行定期的体育锻炼。一个主要障碍是由于繁忙的日程安排而缺乏时间。另一个是认为锻炼必须是高强度的或耗时的才有效。然而，研究表明，即使是适度水平的锻炼，如快走或骑自行车，也可以对大脑健康产生显著益处。
为了鼓励更多人将锻炼纳入日常习惯，公共卫生倡议正在推广“积极生活”的理念。这包括创建支持体育活动的环境，如建设步行道和自行车道，以及鼓励像走楼梯而不是乘电梯这样的活动。通过在日常习惯中做出小改变，个人可以显著改善大脑健康和整体福祉。
总之，体育锻炼不仅对身体健康重要，对维持大脑健康也至关重要。通过增加大脑的血流、减少炎症和改善心理健康，锻炼为增强认知功能和预防神经退行性疾病提供了一种强大的方式。
 
阅读理解题目
What is the main benefit of physical exercise discussed in the passage?
A. Improved physical health
B. Enhanced brain health
C. Increased social interaction
D. Better weight management
Which of the following is a way that exercise benefits the brain according to the passage?
A. By increasing blood flow to the brain
B. By reducing the need for sleep
C. By improving cardiovascular health
D. By increasing appetite
What is the role of BDNF mentioned in the passage?
A. It reduces inflammation in the brain
B. It supports the growth and survival of neurons
C. It enhances cardiovascular function
D. It improves muscle strength
What is a barrier to regular physical exercise mentioned in the passage?
A. Lack of motivation
B. Lack of time due to busy schedules
C. High cost of gym memberships
D. Limited access to exercise facilities
What can be inferred about the importance of exercise from the passage?
A. It is only important for physical health
B. It has no impact on mental health
C. It is crucial for maintaining brain health
D. It is less important than diet for overall well-being
 
题目解析
正确答案：B
解析：文章主要讨论了体育锻炼对大脑健康的益处，包括改善认知功能、增强记忆力和降低神经退行性疾病的风险。因此，选项B“增强大脑健康”是正确的。选项A“改善身体健康”虽然正确，但不是文章的重点；选项C“增加社交互动”和选项D“更好的体重管理”未在文中提及。
 
正确答案：A
解析：文章指出，锻炼通过增加大脑的血流和氧气供应来益于大脑健康。因此，选项A“通过增加大脑的血流”是正确的。选项B“减少睡眠需求”、选项C“改善心血管健康”和选项D“增加食欲”未在文中提及。
 
正确答案：B
解析：文章提到，大脑源性神经营养因子（BDNF）支持神经元的生长和存活，并与改善学习和记忆能力有关。因此，选项B“支持神经元的生长和存活”是正确的。选项A“减少大脑中的炎症”、选项C“增强心血管功能”和选项D“提高肌肉力量”未在文中提及。
 
正确答案：B
解析：文章指出，许多人由于繁忙的日程安排而缺乏时间进行定期锻炼。因此，选项B“由于繁忙的日程安排而缺乏时间”是正确的。选项A“缺乏动力”、选项C“健身房会员费用高”和选项D“缺乏锻炼设施”未在文中提及。
 
正确答案：C
解析：文章总结指出，体育锻炼不仅对身体健康重要，对维持大脑健康也至关重要。因此，选项C“对维持大脑健康至关重要”是正确的。选项A“仅对身体健康重要”过于片面；选项B“对心理健康没有影响”与文章内容相反；选项D“对整体福祉的重要性不如饮食”未在文中提及。
 
翻译与词汇解析
physical exercise：体育锻炼
例句：Physical exercise is important for brain health.（体育锻炼对大脑健康很重要。）
cognitive function：认知功能
例句：Exercise can improve cognitive function.（锻炼可以改善认知功能。）
neurodegenerative diseases：神经退行性疾病
例句：Alzheimer's disease is a neurodegenerative disease.（阿尔茨海默病是一种神经退行性疾病。）
brain-derived neurotrophic factor (BDNF)：大脑源性神经营养因子
例句：BDNF supports the growth of neurons.（BDNF支持神经元的生长。）
inflammation：炎症
例句：Exercise reduces inflammation in the brain.（锻炼可以减少大脑中的炎症。）
oxidative stress：氧化应激
例句：Oxidative stress contributes to cognitive decline.（氧化应激导致认知能力下降。）
endorphins：内啡肽
例句：Exercise releases endorphins, which improve mood.（锻炼释放内啡肽，可以改善情绪。）
active living：积极生活
例句：Public health initiatives promote active living.（公共卫生倡议推广积极生活。）