练习一
文章： In recent years, the number of people suffering from allergies has been on the rise. This increase can be attributed to a variety of factors, including changes in our environment and lifestyle. One significant factor is the improvement in hygiene standards. While cleanliness is generally beneficial, it has also led to a decrease in exposure to certain bacteria and allergens that our immune systems need to develop properly. Additionally, the widespread use of antibiotics has disrupted the balance of our gut bacteria, which play a crucial role in maintaining a healthy immune system. Furthermore, the modern diet, which often includes processed foods and lacks sufficient nutrients, can also contribute to the development of allergies. To address this issue, it is important to promote a balanced diet, encourage exposure to a diverse range of environments, and use antibiotics judiciously.

题目： What is the main idea of the passage? A. The number of people with allergies is increasing. B. Modern lifestyle contributes to the rise of allergies. C. Antibiotics are the main cause of allergies. D. A balanced diet can prevent allergies.

答案：B

解析：文章主要讨论了现代生活方式对过敏人数上升的影响，包括卫生标准提高、抗生素的使用以及现代饮食等因素，因此选项B“现代生活方式导致过敏人数上升”是文章的主旨.

练习二
文章： The concept of lifelong learning has become increasingly important in today's fast-paced world. With rapid technological advancements and changes in the job market, individuals need to continuously update their skills and knowledge to remain competitive. Lifelong learning not only helps people adapt to new situations but also promotes personal growth and development. It encourages individuals to be curious, open-minded, and proactive in seeking opportunities for learning. Moreover, lifelong learning can lead to greater job satisfaction and career advancement. By engaging in continuous learning, individuals can stay relevant in their fields and contribute positively to society. Educational institutions and employers also play a crucial role in supporting lifelong learning by providing resources and opportunities for skill enhancement.

题目： What does the author mainly discuss in the passage? A. The importance of lifelong learning. B. The challenges of lifelong learning. C. The methods of lifelong learning. D. The benefits of lifelong learning.

答案：A

解析：文章主要讨论了终身学习的重要性，包括其对个人适应新环境、促进个人成长、提高工作满意度和职业发展等方面的作用，以及教育机构和雇主在支持终身学习中的作用，因此选项A“终身学习的重要性”是文章的主旨.

练习三
文章： In the past few decades, there has been a significant shift in the way people communicate. The advent of digital technology has transformed communication from face-to-face interactions to online exchanges. Social media platforms, instant messaging apps, and email have become the primary means of communication for many people. While this shift has made communication more convenient and efficient, it has also led to concerns about privacy and security. Additionally, the lack of non-verbal cues in online communication can sometimes lead to misunderstandings. However, digital communication has also opened up new opportunities for people to connect with others across the globe and share information instantaneously. It is important for individuals to be aware of the potential risks and benefits of digital communication and to use it responsibly.

题目： What is the passage mainly about? A. The advantages of digital communication. B. The disadvantages of digital communication. C. The impact of digital communication on society. D. The history of communication methods.

答案：C

解析：文章主要讨论了数字通信对社会的影响，包括其带来的便利和效率、隐私和安全方面的担忧、非语言线索缺失导致的误解以及连接全球和即时分享信息的新机会，因此选项C“数字通信对社会的影响”是文章的主旨.