verbal 2nd RC第3篇有一句不明白……求强人解释一下

小伊YSY

Line Although genetic mutations in bacteria and viruses
      can lead to epidemics, some epidemics are caused
      by bacteria and viruses that have undergone no
     significant genetic change. In analyzing the latter,
(5) scientists have discovered the importance of social
     and ecological factors to epidemics. Poliomyelitis,
     for example, emerged as an epidemic in the United
     States in the twentieth century; by then , modern
     sanitation was able to delay exposure to polio until
(10) adolescenceor adulthood, at which time polio
     infection produced paralysis. Previously, infection
     had occurred during infancy, when it typically
     provided lifelong immunity without paralysis. Thus,
     the hygiene that helped prevent typhoid epidemics
(15) indirectly fostered a paralytic polio epidemic.
     Another example is Lyme disease, which is caused
     by bacteria that are transmitted by deer ticks. It
     occurred only sporadically during the late
     nineteenth century but has recently become
(20) prevalent in parts of the United States, largely due
     to an increase in the deerpopulation that occurred
     simultaneously with the growth of the suburbs and
     increased outdoor recreationa l activities in the
     deer's habitat. Similarly, an outbreak of dengue
(25) hemorrhagic fever became an epidemic inAsia in
     the 1950s because of ecological changes that
     caused Aedes aegypti, the mosquito that transmits
     the dengue virus, to proliferate. The stage is now
     set in the United States for a dengue epidemic
(30) because of the inadvertent introduction and wide
     dissemination of another mosquito, Aedes
     albopictus.


12. The passage suggests that a lack of modern
sanitation would make which of the following most
likely to occur?
(A) An outbreak of Lyme disease
(8) An outbreak of dengue hemorrhagic fever
(C) An epidemic of typhoid
(D) An epidemic of paralytic polio among infants
(E) An epidemic of paralytic polio among
adolescents and adults


那个，我虽然大致好像明白了为什么选C，可是有没有大侠牛人能告诉我蓝色部分的字到底和这个题有什么联系？那个Thus后面突然出现的typhoid和之前那一段有什么因果关系吗？

daisy2

翻译：
现代卫生技术能够推迟polio 直至成年，然而成年感染polio会引发paralysis。
之前，（卫生技术不好时）婴儿感染polio，会产生抗体，确保一辈子都不会得paralysis。
所以，卫生技术阻止了typhoid（infancy时期）的爆发，间接促进了paralytic polio epidemic。

xiaozher

楼上说的对！
这个polio infection 在不同时期会引起不同的病。它在infant时期引起typhoid，同时产生对paralytic的终生免疫；在adolescence or adulthood时期引起paralytic。而现代卫生技术延迟了人们感染polio的时间，所以结果是人们不会得typhoid病，但会得paralytic的病。 下面说的就是这个意思。
modern sanitation was able to delay exposure to polio until
adolescenceor adulthood, at which time polio
     infection produced paralysis. Previously, infection
     had occurred during infancy, when it typically
     provided lifelong immunity without paralysis. Thus,
     the hygiene that helped prevent typhoid epidemics
indirectly fostered a paralytic polio epidemic.
因此如果没有现代卫生，就会有很多typhoid病。 D项说婴儿时期的paralytic polio病，本身就是不对的，因为婴儿时期即使感染polio，也不会paralytic，而是typhoid。

anjjule

楼上是学医的吗?如果知道伤寒和小儿麻痹的关系,上面的原文好理解多了,可是仅从字面意思上看到其中的道理很费劲,尤其忽然跳出来个伤寒, ANYWAY谢谢楼上精辟的指点, 考GMAT还真需要通晓百科.

这么说D选项就是错的了,小孩感染了也不得小儿麻痹

再次谢谢dayuyunhai

dayuyunhai

伤寒和小儿麻痹是同一种病菌引起的。婴儿期感染会得伤寒，青春期感染会得小儿麻痹。然而，婴儿期的感染痊愈后可获得终生的免疫。
现代卫生措施避免了婴儿期的感染，却无法避免青春期的感染。（婴儿不会走，卫生能搞好；小孩到处玩，卫生不好搞）。

anjjule

补充一下观点:

12题,问的是没有现代卫生,什么最可能发生? 这里关键的就是这个最most上

关于推迟麻痹到成年阶段的描述不够干脆肯定,且说到婴儿时会产生终生免疫,也就是说推迟的这个功劳还不完全是现代卫生
而后面说到tyhoid时很肯定，没有疑问或补充解释
thus, the hygiene that helped prevent typhoid epidemics indirectly.....
所以这么看下来最可能发生的就是tyhoid了

请知情者来点评下这么解题对不对？？

anjjule

今天又复习到这道题,觉得还是有些模糊,再考这样的题还是可能会选错,有没有人懂的,请进来指点一下呢. 谢谢!!!

anjjule

by then , modern
    sanitation was able to delay exposure to polio until
(10) adolescenceor adulthood, at which time polio
    infection produced paralysis. Previously, infection
    had occurred during infancy, when it typically
    provided lifelong immunity without paralysis. Thus,
    the hygiene that helped prevent typhoid epidemics
(15) indirectly fostered a paralytic polio epidemic.


基于上面的有效信息:
1.需要知道sanitation和hygiene是一回事，《加勒比海盗2》中伊丽莎白指出夹克船长有个人卫生问题，用的是personal hygien
2.  reviously, infection had occurred during infancy, when it typically provided lifelong immunity without paralysis.这句说小孩能产生免疫，所以不太会出现麻痹症状，尽管之前的文字说能帮助延迟症状到成年modern sanitation was able to delay exposure to polio until adolescenceor adulthood, at which time polio infection produced paralysis.而这句话也说了孩童时的感染在成年后将导致成年后麻痹。    文字定位mordern sanitation的文字非常具有迷惑性

3.再看看信息的细微差别
选D的语气是was able to delay     后面的话又在削弱这个语气
选C的语气thus, ....helped prevent   带有总结性的陈述

个人觉得能否作对看是否能看懂这句原话modern
    sanitation was able to delay exposure to polio until
(10) adolescenceor adulthood, at which time polio
    infection produced paralysis. Previously, infection
    had occurred during infancy, when it typically
    provided lifelong immunity without paralysis.

这样的题太容易中招了

小伊YSY

我不是学生物的，不过貌似typhoid和polio是两种病吧，好像一个是伤寒一个是小儿麻痹。

wangquan0322

Line Although genetic mutations in bacteria and viruses
      can lead to epidemics, some epidemics are caused
      by bacteria and viruses that have undergone no
     significant genetic change. In analyzing the latter,
(5) scientists have discovered the importance of social
     and ecological factors to epidemics. Poliomyelitis,
     for example, emerged as an epidemic in the United
     States in the twentieth century; by then , modern
     sanitation was able to delay exposure to polio until
(10) adolescenceor adulthood, at which time polio
     infection produced paralysis. Previously, infection
     had occurred during infancy, when it typically
     provided lifelong immunity without paralysis. Thus,
     the hygiene that helped prevent typhoid epidemics
(15) indirectly fostered a paralytic polio epidemic.
     Another example is Lyme disease, which is caused
     by bacteria that are transmitted by deer ticks. It
     occurred only sporadically during the late
     nineteenth century but has recently become
(20) prevalent in parts of the United States, largely due
     to an increase in the deerpopulation that occurred
     simultaneously with the growth of the suburbs and
     increased outdoor recreationa l activities in the
     deer's habitat. Similarly, an outbreak of dengue
(25) hemorrhagic fever became an epidemic inAsia in
     the 1950s because of ecological changes that
     caused Aedes aegypti, the mosquito that transmits
     the dengue virus, to proliferate. The stage is now
     set in the United States for a dengue epidemic
(30) because of the inadvertent introduction and wide
     dissemination of another mosquito, Aedes
     albopictus.


12. The passage suggests that a lack of modern
sanitation would make which of the following most
likely to occur?
(A) An outbreak of Lyme disease
(8) An outbreak of dengue hemorrhagic fever
(C) An epidemic of typhoid
(D) An epidemic of paralytic polio among infants
(E) An epidemic of paralytic polio among
adolescents and adults


那个，我虽然大致好像明白了为什么选C，可是有没有大侠牛人能告诉我蓝色部分的字到底和这个题有什么联系？那个Thus后面突然出现的typhoid和之前那一段有什么因果关系吗？

-- by 会员 小伊YSY (2011/8/25 13:49:15)

我的理解是typhoid和polio属于同一种疾病不同时期的称谓，typhoid是幼小阶段，此时危害较小，我们容易对其免疫，而polio是成熟阶段，此时会使人瘫痪，这是我的理解，不知是否对你有帮助。