13　life expectancy

用法解析

life expectancy的意思是“（人的）预期寿命”，比如：Life expectancy in Europe has increased greatly in the 20th century．欧洲人的预期寿命在20世纪大幅增长。要表达“预期寿命增长”，可以说an increase in life expectancy，表示下降则是a decline in life expectancy。

实用语境

How has the population structure changed in your country in recent years?

近年来，你们国家的人口结构发生了哪些变化？

In recent years, China has seen a significant increase in the proportion of older people. This is mainly due to advances in healthcare and nutrition, which have led to an increase in life expectancy. As a result, the population is ageing, and this trend is expected to continue in the coming years.

近年来，中国的老年人口比例显著增加。这主要是由于医疗保健和营养方面的进步导致预期寿命（life expectancy）延长。这导致了人口老龄化加剧，预计这一趋势在未来几年仍将持续。