ChaseDream

标题: 最后再问管13 阅读 一题 [打印本页]
作者: 麻集爱    时间: 2004-6-5 19:45
标题: 最后再问管13 阅读 一题


      A small number of the forest


       species of lepidoptera (moths and


       butterflies, which exist as caterpillars


Line       during most of their life cycle) exhibit


  (5)      regularly recurring patterns of popu-


lation growth and decline—such


fluctuations in population are known


as population cycles.  Although many


different variables influence popula-


(10)      tion levels, a regular pattern such as


a population cycle seems to imply a


dominant, driving force.  Identification


of that driving force, however, has


proved surprisingly elusive despite


(15)      considerable research.  The com-


mon approach of studying causes of


population cycles by measuring the


mortality caused by different agents,


such as predatory birds or parasites,


(20)      has been unproductive in the case of


       lepidoptera.  Moreover, population


       ecologists’ attempts to alter cycles


by changing the caterpillars’ habitat


and by reducing caterpillar popula-


(25)      tions have not succeeded.  In short,


the evidence implies that these insect


populations, if not self-regulating, may


at least be regulated by an agent more


intimately connected with the insect than


(30)      are predatory birds or parasites.


      Recent work suggests that this


agent may be a virus.  For many


       years, viral disease had been


reported in declining populations


(35)    of caterpillars, but population ecolo-


gists had usually considered viral


disease to have contributed to the


decline once it was underway rather


than to have initiated it.  The recent


(40)     work has been made possible by


new techniques of molecular biology


that allow viral DNA to be detected


at low concentrations in the environ-


ment.  Nuclear polyhedrosis viruses


(45)      are hypothesized to be the driving


force behind population cycles in


lepidoptera in part because the


viruses themselves follow an infec-


tious cycle in which, if protected from


(50)      direct sun light, they may remain


virulent for many years in the envi-


ronment, embedded in durable


crystals of polyhedrin protein.


Once ingested by a caterpillar,


(55)      the crystals dissolve, releasing


the virus to infect the insect’s cells.


Late in the course of the infection,


millions of new virus particles are


formed and enclosed in polyhedrin


(60)      crystals.  These crystals reenter the


environment after the insect dies and


decomposes, thus becoming avail-


able to infect other caterpillars.


      One of the attractions of this


(65)      hypothesis is its broad applicability.


Remarkably, despite significant differ-


ences in habitat and behavior, many


species of lepidoptera have population


cycles of similar length, between eight


(70)      and eleven years.  Nuclear polyhe-


drosis viral infection is one factor these


disparate species share.


--------------------------------------------------------------------------------


Q34:


Which of the following, if true, would most weaken the author’s conclusion in lines 25-30?


              



  • New research reveals that the number of species of birds and parasites that prey on lepidoptera has dropped significantly in recent years.

  • New experiments in which the habitats of lepidoptera are altered in previously untried ways result in the shortening of lepidoptera population cycles.

  • Recent experiments have revealed that the nuclear polyhedrosis virus is present in a number of predators and parasites of lepidoptera.

  • Differences among the habitats of lepidoptera species make it difficult to assess the effects of weather on lepidoptera population cycles.

  • Viral disease is typically observed in a large proportion of the lepidoptera population.

    • Answer: c我b


    不用看我的答案了但答案我不明白为什么选c 。

    我就不会作阅读里的逻辑，每做每错。 请高手给些指点，为什么一作阅读逻辑就错？？
    作者: fair_sword    时间: 2004-6-5 22:20

    全文结构现象解释型：

    第一段：现象及第一个解释

    第二段：正确的解释

    第三段：2段的解释好啊！

    做逻辑题，必须看出问题的论证结构：The com-

    mon approach of studying causes of

    population cycles by measuring the

    mortality caused by different agents,

    such as predatory birds or parasites,

    (20)      has been unproductive in the case of

           lepidoptera. （试验结果1，evidence 1) Moreover, population

           ecologists’ attempts to alter cycles

    by changing the caterpillars’ habitat

    and by reducing caterpillar popula-

    (25)      tions have not succeeded.(evidence 2)  In short,

    the evidence(多清楚的论证关系） implies that these insect

    populations, if not self-regulating, may

    at least be regulated by an agent more

    intimately connected with the insect than

    (30)      are predatory birds or parasites.（结论）

    结论就是鸟和parasites不是主要的regulator.

    削弱的目的就是鸟和parasites是主要的regulator.

    现在来分析选项差别：

    1. New research reveals that the number of species of birds and parasites that prey on lepidoptera has dropped significantly in recent years. (无关）
    2. New experiments in which the habitats of lepidoptera are altered in previously untried ways result in the shortening of lepidoptera population cycles.（在环境evidence2和小鸟evidence1之间架了桥梁，加强）
    3. Recent experiments have revealed that the nuclear polyhedrosis virus is present in a number of predators and parasites of lepidoptera. (在病毒和小鸟间架了桥。全文结论是病毒导致变化。这里说病毒来自小鸟。）
    4. Differences among the habitats of lepidoptera species make it difficult to assess the effects of weather on lepidoptera population cycles. （天气无关吧，即使把天气和病毒联系起来，还是无法对这个结论削弱）
    5. Viral disease is typically observed in a large proportion of the lepidoptera population.（无关）
    作者: 醋醋妹妹    时间: 2004-6-6 04:44

    "In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites."---昆虫的数量的变化更多是由其他因素决定, 而非鸟类或寄生虫.

    问题要你weaken这句话, 那么就是说昆虫的数量变化更多与鸟类相关. 那么我们就看选项中那个表示这个意思, 哪怕是搭个边. 在五个选项比较中, C更能表达鸟吃虫的那种意思. 大量的鸟吃了很多感染有这种病毒的虫子. 呵呵...

    作者: fair_sword    时间: 2004-6-7 11:24
    以下是引用醋醋妹妹在2004-6-6 4:44:00的发言：

    "In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites."---昆虫的数量的变化更多是由其他因素决定, 而非鸟类或寄生虫.


    简而言之，the evidence implies that 这些昆虫的数量，如果不是自我调节，可能至少是被一个与昆虫更密切联系的 agent调节，而不是鸟类或寄生虫。


    问题要你weaken这句话, 那么就是说昆虫的数量变化更多与鸟类相关. 那么我们就看选项中那个表示这个意思, 哪怕是搭个边. 在五个选项比较中, C更能表达鸟吃虫的那种意思. 大量的鸟吃了很多感染有这种病毒的虫子. 呵呵...


    使用相关和无关来判断选择时，还应该注意求同和求异的比较。B是相关选项，求同，妹妹仔细想想。c:Recent experiments have revealed that the nuclear polyhedrosis virus is present in a number of predators and parasites of lepidoptera. 这句话的意思是试验发现virus存在在一些鸟和parasites。


    要削弱的结论如下：鸟和parasites不是影响虫的主要因素。


    全文论证关系如下：

    1.一些影响鸟和parasites的试验（1，2），得出鸟和parasites不是影响虫的主要因素。

    2.分子技术发现是virus导致的。

    C:选项的削弱方式就是在2和1之间架桥。 说明，virus是通过鸟和parasites传染给insects的。 就是说其实还是鸟和parasites在间接的regulate 昆虫。


    作者: 麻集爱    时间: 2004-6-9 10:48
    xiexie  feichangganxie
    作者: nainainono    时间: 2017-6-15 10:42
    为什么这道题og 的答案是b？？？
    作者: Fr.Yang    时间: 2019-3-9 02:24
    nainainono 发表于 2017-6-15 10:42
    为什么这道题og 的答案是b？？？

    对的啊。为什么是b？




    欢迎光临 ChaseDream (https://forum.chasedream.com/) Powered by Discuz! X3.3