n the period during which something is functional (as between birth and death)
n. 预期生命期限；寿命；预期使用期限
1. A dog's lifespan is usually around 10 to 15 years.
狗的寿命通常在10到15年之间。
2. Scientists study the lifespan of different species to understand their health.
科学家研究不同物种的寿命以了解它们的健康状况。
3. Eating healthy can help increase your lifespan.
健康饮食可以帮助延长你的寿命。