GWD13-36 Cannot differentiate btw A and C

yukon

又看了一遍，感觉34提出的实在是不好。

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.（line25-30)

看看这个要weaken的对像：“一定有别的因素，此因素与这种昆虫的关系比掠食者及寄生虫更加紧密“（翻译的不好，大概是这个意思，没有遗漏吧？）conclusion里没说此因素比掠食者、寄生虫、栖息地更重要，也没说此因素比掠食者、寄生虫等其他因素更重要。

B就提出了个habitats of lepidoptera的概念。如果不看上文，只就line25-30而言，B选项简直像个support!

yahoow

以下是引用yukon在2005-6-28 11:09:00的发言：

又看了一遍，感觉34提出的实在是不好。

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.（line25-30)

看看这个要weaken的对像：“一定有别的因素，此因素与这种昆虫的关系比掠食者及寄生虫更加紧密“（翻译的不好，大概是这个意思，没有遗漏吧？）conclusion里没说此因素比掠食者、寄生虫、栖息地更重要，也没说此因素比掠食者、寄生虫等其他因素更重要。

B就提出了个habitats of lepidoptera的概念。如果不看上文，只就line25-30而言，B选项简直像个support!

同感！同感！ETS越来越变态！！

无尾小恶魔

我还是不明白为什么35题要选A，existence 和cause 是不同意思吧~我支持D， 因为我觉得这里提出的是反面例子

透明萝卜

以下是引用cdg2004在2005-6-17 17:27:00的发言：

Q34:

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

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


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


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


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


5. Viral disease is typically observed in a large proportion of the lepidoptera population.---support

B--栖息地的改变导致循环缩短。---假设循环周期为8-11年，根据B的意思栖息地的改变导致周期降到5年，---但折并不能解释栖息地的改变是产生这种循环的原因呀。

C---病毒存在于大量的捕食者中。---由于捕食者，导致病毒感染昆虫，产生人口循环。---weaken--I VOTE C.

Q37:

According to the passage, before the discovery of new techniques for detecting viral DNA, population ecologists believed that viral diseases

1. were not widely prevalent among insect populations generally


2. affected only the caterpillar life stage of lepidoptera


3. were the driving force behind lepidoptera population cycles


4. attacked already declining caterpillar populations


5. infected birds and parasites that prey on various species of lepidopte

Answer: D

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.  

I vote B.   but...had usually...it was underway rather than...initiated it. 其中，underway是否可以理解为B的life stage?

请NN指教。

红体字部分意思如何理解呢？

amy9301

junguo21c

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.

这个红字部分我刚开始也没有理解，仔细看了看，是不是可以这样解释，

“人口生态学家是认为病毒对毛毛虫的减少确实起作用了，（once）但是只是在

毛毛虫（underway感染了病毒以后加速其死亡），并不是毛毛虫死亡的直接引发原因（

rather than to have initiated it）。”

根据这个理解37可以选择D

amysarmy

那37题选D吗?

可是我觉得选B啊..文章中不是说当虫虫死了病毒就潜伏,一旦它被一只虫给消化吸收了,病毒就开始肆虐了吗..

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.

这不就是B所说的病毒只能在虫活着的时候影响到它们吗?

amysarmy

我错了我错了..原来题目问的是之前的看法啊...呵呵.

不好意思啊..傻啦吧叽的我..