n.外形，外在性，外部事物，（经济学名词）外部效应

原形：externality复数：externalities

The pollution caused by factories is a classic example of an externality.
工厂造成的污染是一个典型的外部性的例子。
The use of pesticides in agriculture can create negative externalities on nearby ecosystems.
农业中使用农药可能会对附近生态系统产生负面影响，这是一个外部性。
Externalities can arise when consumers do not fully internalize the costs or benefits of their actions, as in the case of cigarette smoking.
当消费者没有完全内化其行为的成本或效益时，如吸烟情况，就会出现外部性。
Education has positive externalities for society as educated individuals contribute more to the economy and social well-being.
教育对于社会具有正面外部性，因为受过良好教育的个人能更多地贡献于经济和社会福祉。
The construction of a new highway may generate both positive (increased accessibility) and negative (land degradation) externalities.
新建一条高速公路可能产生正向（增加可达性）和负向（土地退化）两种外部性。
Investment in renewable energy projects helps mitigate climate change externalities that would otherwise burden future generations.
投资可再生能源项目有助于缓解原本将给后代带来负担的气候变化外部性。
The spillover effects of research and development activities in high-tech industries represent a significant positive externality.
高科技产业的研发活动产生的溢出效应构成了一种重要的正面外部性。
Unregulated hunting can lead to over-exploitation of wildlife resources and create a negative externality on biodiversity conservation efforts.
无节制的狩猎可能导致野生动植物资源过度开发，并对生物多样性保护工作产生负面外部性。
A congestion charge for driving in a city center is a policy designed to address the negative externality created by traffic jams.
对驶入市中心收取拥堵费是一种旨在解决交通堵塞所产生的负面外部性的政策。
When a company invests in worker training programs, it generates positive externalities by improving labor market productivity overall.
当企业投资于员工培训计划时，它通过提高整体劳动力市场的生产效率而产生了正面外部性。