OG 12 第一题

DayDreamings

“Life expectancy” is the average age at death of the
entire live-born population. In the middle of the
nineteenth century, life expectancy in North America
was 40 years, whereas now it is nearly 80 years.
Thus, in those days, people must have been
considered old at an age that we now consider the
prime of life.
Which of the following, if true, undermines the
argument above?
(A) In the middle of the nineteenth century, the
population of North America was significantly
smaller than it is today.
(B) Most of the gains in life expectancy in the last
150 years have come from reductions in the
number of infants who die in their first year
of life.
(C) Many of the people who live to an advanced age
today do so only because of medical technology
that was unknown in the nineteenth century.
(D) The proportion of people who die in their
seventies is significantly smaller today than is the
proportion of people who die in their eighties.
(E) More people in the middle of the nineteenth
century engaged regularly in vigorous physical
activity than do so today.

不太明白为什么D选项是support the argument????

painsper

原文的意思是life expectancy平均寿命 40→80 然后说，原来那年的某个年龄在那个年代是老的，但是现在确是年轻的。比如，原来60岁是老的，那么现在60就是年轻的。这个推理的逻辑是，大部分原来的死亡高龄的应该比较少。因为，如果高龄的人原来很多，那么在原来和现在的情况是一样的，自然不会出现原文说的当时的老等于现在的年轻

加强：D说的是 现在70左右死的比80的少，也就是80岁左右死的比较多。那么原来就是80岁死的比较少。这样的选项是符合原意的，原来高龄死亡少

看削弱来理解这个题：削弱说的是，婴儿死比较多那个年代，所以其实那个年代别的死亡情况是一样的，只是婴儿多，所以平均下降了。那么久削弱了

好难解释。。

daoyinger

这题答案是什么啊

DayDreamings

答案是B

DayDreamings

不好意思~~  还是没明白为什么D是加强

EGHJUYMN

原题论据
1. 过去的人平均年龄 40岁。
2. 现在人平均年龄 80岁。
结论，过去40岁，到现在正值壮年。

加强: 过去的人基本到40岁死光光了，没有太多人活过40岁。
    现在人基本都到80岁死光光，也就是大部分人都能活到80岁。(D选项要表达的意思。)

削弱: 过去婴儿死亡率高，其实大部分人还是可以活到80岁的，一平均就到40岁了。