【F1】The concept of life expectancy at birth is well understood by most people: the average age in which babies bom today will di

admin2019-08-08  14

问题    【F1】The concept of life expectancy at birth is well understood by most people: the average age in which babies bom today will die if death rates throughout their life course resemble those today. We have known for decades that in the U.S., on average, women live longer than men; whites live longer than blacks; and the rich and well educated live longer than those with low socioeconomic status.
   【F2】What we are only recently beginning to understand, however, is that educational attainment is becoming the single most important social determinant of longevity in America. The new research shows that college-educated white women are expected to live 9.3 years longer than their low-educated counterparts—those who have not completed high school—compared with only a 2.5-year difference in 1990.
   Variation is perhaps the second most important measure in statistics—the first being the average— summarizing the extent to which observations are spread around the average. 【F3】For example, we can observe two populations with identical life expectancy, but, from an individual perspective, the one with larger variation in life spans will have greater uncertainty in the age of death. If life span variation is very small, most deaths are concentrated close to the average; if variation is large, some individuals will die prematurely, whereas others will survive to a very old age.
   To put it concretely, if you had to bet on how long you will live, your best bet would depend more than anything else on your educational attainment. 【F4】Although betting on how long we will live may seem like an odd endeavor, this is precisely what we do, whether implicitly or explicitly, when we make decisions throughout the course of our life.
   Variation in life spans also affects the social and economic institutions planning for our old age, including the Social Security Administration and programs like Medicare. They too have to balance between contributions and benefits in an era of growing uncertainty about how long we will live. Perhaps more fundamental, the growing inequality in life spans—both in average and in variability—raises questions concerning distributive justice. 【F5】For example, if those at the lower rungs of the socioeconomic ladder are less likely to survive to old age—and, importantly, face greater uncertainty about their chances of survival—should we institute a differential retirement age? And what would such a scheme look like?
【F1】

选项

答案大部分人对出生时的预期寿命这个概念有很好的理解:如果在婴儿生命历程中的死亡率还和今天一样,那么今天出生的婴儿也会在平均年龄死去。

解析 ①本句为主从复合句。冒号前为主句,冒号后至句末为同位语从句,解释说明主句主语The concept of life expectancy at birth的内容。②主句为被动语态的主谓宾结构;at birth为后置定语修饰life expectancy.意为“出生时的预期寿命”。③冒号后同位语从句包含一个定语从句和一个条件状语从句。从句主句将宾语前置于句首,由定语从句in which...修饰,正常语序应为babies born today will die in the average age,其中born today为过去分词作后置定语修饰babies,意为“今天出生的婴儿”。④从句中的介词短语throughout their life course为后置定语,their指代主句中的babies,death rates throughout…course意为“在这些婴儿生命历程中的死亡率”;代词those指代death rates。
转载请注明原文地址:https://kaotiyun.com/show/2F2Z777K
0

随机试题
最新回复(0)