Some animals are nocturnal, meaning they are active at night and sleep during the day.
81.一些动物是夜行性的，这意味着它们在夜间活跃，白天睡觉。
The study of genetics has led to many breakthroughs in understanding how traits are passed from one generation to the next.
82.遗传学研究在理解性状如何从一代传递到下一代方面取得了许多突破。
The use of artificial intelligence is becoming more widespread in various fields, such as healthcare, finance, and transportation.
83.人工智能的使用在医疗保健、金融和交通等各个领域变得越来越广泛。
The importance of protecting the environment cannot be overstated, as it is essential for the survival of all living beings.
84.保护环境的重要性怎么强调都不为过，因为它对所有生物的生存至关重要。
Some cultures have elaborate wedding traditions that include specific rituals, clothing, and celebrations.
85.一些文化有精心设计的婚礼传统，包括特定的仪式、服饰和庆祝活动。
The field of psychology studies human behavior and mental processes, including how people think, feel, and interact.
86.心理学领域研究人类行为和心理过程，包括人们如何思考、感受和互动。
The construction of large - scale infrastructure projects, such as bridges and tunnels, requires significant investment and engineering expertise.
87.大型基础设施项目（如桥梁和隧道）的建设需要大量投资和工程专业知识。
Many ancient civilizations had their own writing systems, which were used to record history, laws, and religious beliefs.
88.许多古代文明都有自己的书写系统，用于记录历史、法律和宗教信仰。
The popularity of e - books has grown in recent years, but printed books still have a significant place in the market.
89.近年来电子书的普及程度有所提高，但纸质书在市场上仍占有重要地位。
The concept of national identity is complex and can be influenced by factors such as language, culture, and history.
90.国家认同的概念很复杂，可能受到语言、文化和历史等因素的影响。