一、基础用法

1. The school organizes various extracurricular activities every semester.

（学校每学期组织各种课外活动。）

2. She likes to engage in physical activities to stay fit.

（她喜欢进行体育活动以保持健康。）

二、搭配与短语

1. participate in / take part in

- The students participated in the school debate.

- We took part in a community service project.

（学生参加了学校辩论；我们参与了一个社区服务项目。）

2. a wide range of activities

- The park offers a wide range of activities for families.

（公园为家庭提供广泛的活动选择。）

3. favorite activity

- His favorite activity is playing guitar.

（他最喜欢的活动是弹吉他。）

三、特殊用法

1. geological activity

- The region is known for its volcanic geological activity.

（该地区以火山地质活动闻名。）

2. inactivity

- Lack of activity can lead to health problems.

（缺乏活动可能导致健康问题。）

四、复杂句式

1. The company's marketing strategy focuses on customer engagement activities.

（公司的营销策略侧重客户参与活动。）

2. Despite the rain, the festival continued with various engaging activities.

（尽管下雨，节日仍通过各种吸引人的活动继续进行。）

这些例句展示了"activity"在日常生活、学术写作和专业领域中的多样化应用，可根据具体语境选择合适表达。