GRE閱讀｜The defoliation of millions of acres of trees by massive infestations of gypsy moth caterpillars－熱血背包客莊ㄟ

The defoliation of millions of acres of trees by massive infestations of gypsy moth caterpillars is a recurring phenomenon in the northeastern United States. In studying these outbreaks, scientists have discovered that affected trees fight back by releasing toxic chemicals, mainly phenols, into their foliage. These noxious substances limit caterpillars' growth and reduce the number of eggs that female moths lay. Phenols also make the eggs smaller, which reduces the growth of the following year's caterpillars. Because the number of eggs a female moth produces is directly related to her size, and because her size is determined entirely by her feeding success as a caterpillar, the trees' defensive mechanism has an impact on moth fecundity.

The gypsy moth is also subject to attack by the nucleopolyhedrosis virus, or wilt disease, a particularly important killer of the caterpillars in outbreak years. Caterpillars contract wilt disease when they eat a leaf to which the virus, encased in a protein globule, has become attached. Once ingested by a caterpillar, the protein globule dissolves, releasing thousands of viruses, or virions, that after about two weeks multiply enough to fill the entire body cavity. When the caterpillar dies, the virions are released to the outside, encased in a new protein globule synthesized from the caterpillar's tissues and ready to be picked up by other caterpillars.

Knowing that phenols, including tannins, often act by associating with and altering the activity of proteins, researchers focused on the effects on caterpillars of ingesting the virus and leaves together. They found that on tannin-rich oak leaves, the virus is considerably less effective at killing caterpillars than when it is on aspen leaves, which are lower in phenols. In general, the more concentrated the phenols in tree leaves, the less deadly the virus. Thus, while highly concentrated phenols in tree leaves reduce the caterpillar population by limiting the size of caterpillars and, consequently, the size of the female's egg cluster, these same chemicals also help caterpillars survive by disabling the wilt virus. Forest stands of red oaks, with their tannin-rich foliage, may even provide caterpillars with safe havens from disease. In stands dominated by trees such as aspen, however, incipient gypsy moth outbreaks are quickly suppressed by viral epidemics.

Further research has shown that caterpillars become virtually immune to the wilt virus as the trees on which they feed respond to increasing defoliation. The trees' own defenses raise the threshold of caterpillar vulnerability to the disease, allowing populations to grow denser without becoming more susceptible to infection. For these reasons, the benefits to the caterpillars of ingesting phenols appear to outweigh the costs. Given the presence of the virus, the trees' defensive tactic apparently has backfired.

1. It can be inferred from the passage that wilt disease virions depend for their survival on

(A) protein synthesized from the tissues of a host caterpillar

(B) aspen leaves with high concentrations of phenols

(D) nutrients that they synthesize from gypsy moth egg clusters

(E) a rising threshold of caterpillar vulnerability to wilt disease

2.Which of the following best describes the function of the third paragraph of the passage?

(A) It resolves a contradiction between the ideas presented in the first and second paragraphs.

(B) It introduces research data to support the theory outlined in the second paragraph.

(D) It shows how phenomena described in the first and second paragraphs act in combination.

(E) It elaborates on the thesis introduced in the first paragraph after a digression in the second paragraph.

3. Select the sentence in the passage that the author uses as a supporting idea to explicate how gypsy moth caterpillars become immune to the wilt virus.

For the following question, consider each of the choices separately and select all that apply

4.Which of the following statements about gypsy moth caterpillars is supported by information presented in the passage EXCEPT?

(A) Differing concentrations of phenols in leaves have differing effects on the ability of the wilt virus to kill gypsy moth caterpillars.

(B) Female gypsy moth caterpillars stop growing after they ingest leaves containing phenols.

(C) The longer a gypsy moth population is exposed to wilt disease, the greater the likelihood that the gypsy moth caterpillars will become immune to the virus.

結構分析：

別被這麼長的文章嚇到了，怎麼化繁為簡呢？聽我說來。

第一段：

The defoliation of millions of acres of trees by massive infestations of gypsy moth caterpillars is a recurring phenomenon in the northeastern United States. In studying these outbreaks, scientists have discovered that affected trees fight back by releasing toxic chemicals, mainly phenols, into their foliage. These noxious substances limit caterpillars' growth and reduce the number of eggs that female moths lay. Phenols also make the eggs smaller, which reduces the growth of the following year's caterpillars. Because the number of eggs a female moth produces is directly related to her size, and because her size is determined entirely by her feeding success as a caterpillar, the trees' defensive mechanism has an impact on moth fecundity.

The defoliation of millions of acres of trees by massive infestations of gypsy moth caterpillars is a recurring phenomenon in the northeastern United States.

第一句話絕對不可少，表示文章方向用的，探討的東西是，ＧＭ造成的落葉效應再現，所以整個文章應該是往gypsy moth跟defoliation間的消長

整個第一段只需要看第一句即可，為何呢？紅色部分都是關鍵詞，首先看到In studying these outbreaks其實他中間有個代名詞，後面的outbreaks先不要直接翻中文，因為代名詞加上一個概念名詞，往往都是對上面一段做統整，所以我們對outsbreak的感受就是去找前面的內容是在描述一種很糟的情況即可，而這樣把代名詞對應完之後，再看到他前面的in，這也是表修飾用的，我在某個東西裡面看到什麼鬼，這也是已經在進路細節展開了，所以接下來內容必為主幹these outbreaks裡面的東西，接著scientists have discovered that這也是個舉例解釋的訊號字，某人發現某事，表示事情已經定奪了，就是一件具體事實，那這樣的話就等於是在對上一句話主題句作抽象轉具體，或是概論轉細節用的，所以跳過此句，再來Phenols這個字首先他必然是專有名詞，而且在文章的第一句話連個影子都沒有，反而是在第二句話裡面發現的，既然是在細節中發現的東西，那這句話又被細節中的細節當主幹用，那可想而知重要性根本是零，而面對這類方式就是眼不見為淨，最後兩個Because 連接表示做一個解釋說明，但其實關注主幹的時候，這些解釋都是多餘的，注意到他的結果即可，再來就文法來說because所在的完整子句就是要組表條件的副詞子句去修飾到主幹用的，既然身份是修飾詞，必非主幹也，這些原因考試有出在看，所以人在說做事要有頭有尾，哈哈確實如此，的確是有頭有尾。

the trees' defensive mechanism has an impact on moth fecundity.

樹的自衛跟蛾之間的影響，不過話說the trees' defensive mechanism我又對這個有意見了，既然這幾字前面有提過（the trees），但是又跟主題句無關，表示他應該是在對主題句的gypsy moth跟defoliation間的消長，他們的彼此影響做補充，也就是說假設問到為什麼會造成兩者之間的消長，那他the trees' defensive mechanism可能就答案了，所以不用太理會，坦白說我看到the 就沒再看下去了，因為他後面是tree，而為了整體連貫，這棵樹一定是主題句講的那顆The defoliation of millions of acres of trees，那接下來defensive mechanism這不就是被強迫對應到defoliation了，我先不關他們是不是等號，但我能確定他們之間必然可能寫成一組函數y=f(X)，Y=defoliation ，X= defensive，所以他只是在針對本段做封裝迴文而已，庵根本連理都可以不用理。

第二段：

The gypsy moth is also subject to attack by the nucleopolyhedrosis virus, or wilt disease, a particularly important killer of the caterpillars in outbreak years.

開頭給個ＧＭ哇主角啊，先來看到also，這也是表並列，而且他是跟主題句同樣是主幹的gypsy moth綁在一起，所以這也是主幹的另外一個東西了，他說對於the nucleopolyhedrosis virus, or wilt disease，這兩樣也很容易受影響，所以綜觀以上P1:GM導致落葉，然後P2:ＧＭ被NV / WD 影響。

接下來也是連讀都不用讀了，綠色對到紅色，再來黃色的邏輯詞都表示一種條件情況的特例，那我可以不用理他，舉例表示整個歷史過程當中的某一個點發生的某件事情，你可以說這理論如何如何，你看我舉個例子，但是反過來，是不能有某特定的點去延伸成一組函數的，因為每個人對這個點的未來過去的想法都不一樣，他很有可能會有無限多種函數經過此一點，而你也很難以解析延拓，去得到方程式，他既然如此，某個時間段就被我當成細節處理了，細節的下場就是，亂我主幹者，必殺之～～掰掰。

第三段：

這裡光是開頭就是細節上的內容，那基本上他連看都不用看了，想必他應該是針對phenols繼續延伸，但是這跟主幹，P1:GM導致落葉，然後P2:ＧＭ被影響NV / WD，扯遠了，必然是在做支持用，可能會是Ｐ是關係到ＧＭ是多事少的因子之一，真的沒必要看，反倒是有轉折詞這倒是滿吸引人的，來看看到比會不會影響到文意，因為沒次遇到轉折都不會有好事發生，我做這麼多篇考題去了，幾乎都會變成考點。

In stands dominated by trees such as aspen, however, incipient gypsy moth outbreaks are quickly suppressed by viral epidemics.

確實是對影響因子提出反駁，舉出一組特例aspen＝tree去反駁，可是看了一下內容感覺跟不搭，因為他跟第二段主題句說ＮＶ會影響差不多意思啊，所以那個however，到底跟誰轉折。就要往上看，好了，找到對象對比了，red oaks VS. aspen，safe havens VS. suppressed by viral，所以是細節內的轉折，不太需要記，因為他想說了phenols，然後這個Ｐ又跟tannin有關，接著再去連到virus，最後才導出此結果，這都是很後面的東西了，但我就是不放心，因為這很容易變成考點，所以如果要記筆記的話，就是ＲＯ→ good，Ａ→bad。

第四段：

這段只關注到第一句即可，第二句定冠詞出現，直接砍，第三句跟第四句，都有表示原因的字眼，砍！

所以專心把第一句話看完就可以做題目了

Further research has shown that caterpillars become virtually immune to the wilt virus as the trees on which they feed respond to increasing defoliation.

這是遞進的詞彙，所以邏輯上是延續下來的，所以表示贊成主題，那就是，P1:GM導致落葉，然後P2:ＧＭ被影響NV / WD

看來是把他們整合起來，這裡有毛毛蟲，就是ＧＭ，接著給到病毒，ＧＭ不被Ｖ影響，後面掛個條件，當DE＋＋↑，所以可以這麼說ＧＭ，ＤＥ＋＋，Ｖ--

總結：

看完之後，我發現他好像有點無限迴圈，感覺像是那種五行相剋之類的概念，你看喔，原本ＧＭ會造成落葉，然後，NV/WD會讓ＧＭ變少，最後一段假設落葉越多，結果NV/WD反而減少，使得ＧＭ活下來，然後那個細節Ｐ又會削弱WD/NV，而細節Ｐ是因為落葉的反擊，這就好笑了，本來樹葉要反擊ＧＭ生成Ｐ，但是呢，Ｐ會使病毒戰鬥力變弱，既然戰鬥力下降，自然打不死ＧＭ，而ＧＭ打不死，又使落葉繼續增加，結果，落葉繼續增加，使得樹木又想做反擊，我怎麼想來想去都是樹木吃虧啊，那這個機制怎麼沒有因進化而淘汰掉啊，怪怪～～～感覺上好像就是火上加油，ＤＥ越多，ＧＭ活得越好。但我不管正確翻譯是啥，我確保題目都答對就好，而以上內容只需要看五句話，下面的圖就出來了，其他內容有考再說。

1. It can be inferred from the passage that wilt disease virions depend for their survival on

(A) protein synthesized from the tissues of a host caterpillar

(B) aspen leaves with high concentrations of phenols

(D) nutrients that they synthesize from gypsy moth egg clusters

(E) a rising threshold of caterpillar vulnerability to wilt disease

解題：

推理題，就是找對比對象了，wilt disease virions depend for their survival on，他們是怎樣活下去的，既然是推理題，絕不會在文章中找到他們因為如何如何而存活，對比啊，所以跟他對比的東西，要嘛就是『死VS.活』，不然就是wilt disease virions VS. 某病毒，之類的，接著題目會給予兩者之間的邏輯性，看是要取反還是取同，再代入對應的文章內容，那這邊怎麼找，ＷＤ的就是第二段了，所以目標訂為到第二段，開始掃描，

The gypsy moth is also subject to attack by the nucleopolyhedrosis virus, or wilt disease, a particularly important killer of the caterpillars in outbreak years. （可是我沒看到內容啊，沒有說到活，他只有說到這東西的屬性特徵怎樣，所以不是這句）

Caterpillars contract wilt disease when they eat a leaf to which the virus, encased in a protein globule, has become attached. （contract連接....接觸，怪怪的，往下再找）

Once ingested by a caterpillar, the protein globule dissolves, releasing thousands of viruses, or virions, that after about two weeks multiply enough to fill the entire body cavity. （主角wilt disease沒了，跳過...）

When the caterpillar dies, the virions are released to the outside, encased in a new protein globule synthesized from the caterpillar's tissues and ready to be picked up by other caterpillars.

太好了找到對應字了，那個die VS. survival，接著就看他們兩者關係，沒問題的可以找到第一句，attack by，所以ＧＭ跟ＮＶ必然存在反向對立的情況，所以回來看目標句，the caterpillar dies就等於wilt disease virions depend for their survival on。所以後面內容直接對應就是答案了，a new protein globule synthesized from the caterpillar's tissues對應到（Ａ），選（Ａ）

2.Which of the following best describes the function of the third paragraph of the passage?

(A) It resolves a contradiction between the ideas presented in the first and second paragraphs.

(B) It introduces research data to support the theory outlined in the second paragraph.

(D) It shows how phenomena described in the first and second paragraphs act in combination.

(E) It elaborates on the thesis introduced in the first paragraph after a digression in the second paragraph.

解題：

由結構圖看第三段功能就是舉例了，所以不會有負向字出現，（Ａ）contradiction，（Ｃ）conflicting，（Ｅ）digression先刪除，剩下來就是抓第三段主題，那當然就是主題句了。

Knowing that phenols, including tannins, often act by associating with and altering the activity of proteins,...看到這裡應該就知道答案了吧。疑心病重的話researchers focused on the effects on caterpillars of ingesting the virus and leaves together. 都雙連擊了，別再糾結了，選（Ｄ）

3. Select the sentence in the passage that the author uses as a supporting idea to explicate how gypsy moth caterpillars become immune to the wilt virus.

解題：

主角是supporting idea to explicate how gypsy moth caterpillars become immune to the wilt virus.，然後找一句作用是用來解釋他的，所以就是要找細節，舉例，解釋這類屬性的句子，再來問題比較大的是到底看哪一句，由剛剛在檢視結構圖時，只有第四段有提到『免疫』，那我們就從那邊出發吧，

接下來在找到For these reasons，我是在抓回答第四段主題句的原因喔，第一句是主題句表概念陳述他是『被』解釋的對象，因此絕不是當事人，而第三句話前面出現these reasons，他是代名詞啊，代替前面的東西，啊前面也只有兩句話可以找，嘿嘿，表示是第二句就是答案，阿你的值域就只能是第二句啊，被夾攻，選到：

The trees' own defenses raise the threshold of caterpillar vulnerability to the disease, allowing populations to grow denser without becoming more susceptible to infection.

補充：其實我覺得GRE的這一題很像托福考試的句子插入題，都比較像是由邏輯跟代名詞來引導出答案的考題

For the following question, consider each of the choices separately and select all that apply

4.Which of the following statements about gypsy moth caterpillars is supported by information presented in the passage EXCEPT?

(A) Differing concentrations of phenols in leaves have differing effects on the ability of the wilt virus to kill gypsy moth caterpillars.

(B) Female gypsy moth caterpillars stop growing after they ingest leaves containing phenols.

(C) The longer a gypsy moth population is exposed to wilt disease, the greater the likelihood that the gypsy moth caterpillars will become immune to the virus.

解題：

要開始煉丹了，碰到多選，又取非題，嘿嘿認命一點

(A) Differing concentrations of phenols in leaves have differing effects on the ability of the wilt virus to kill gypsy moth caterpillars.

哇剛好是第三段的內容，也就結構圖上的ＲＯ→ good，Ａ→bad，所以也差異存在，他是對的不要選，呼～～好險剛剛有順便記下來

(B) Female gypsy moth caterpillars stop growing after they ingest leaves containing phenols.

專為女性，這就怪了，因為第三段主題是，Knowing that phenols, including tannins, often act by associating with and altering the activity of proteins, researchers focused on the effects on caterpillars of ingesting the virus and leaves together，沒有分男女啊，垃圾也不分藍綠，所以他是錯的，可是不放心就往下一句看，因為這一句的內容是存在於researchers裡頭的，所以後面剛好They found tha....表示同一件事情繼續補充

They found that on tannin-rich oak leaves, the virus is considerably less effective at killing caterpillars than when it is on aspen leaves, which are lower in phenols.

所以更加確定這選項是錯的，文章比的是品種，選項比的是男女，這扯遠了。

(C) The longer a gypsy moth population is exposed to wilt disease, the greater the likelihood that the gypsy moth caterpillars will become immune to the virus.

ＧＭ跟ＷＤ的關係，所以跑到第二段去了，不對，因為後面還有immune，所以應該是第四段：

Further research has shown that caterpillars become virtually immune to the wilt virus as the trees on which they feed respond to increasing defoliation.

然後接下來補充說到：

The trees' own defenses raise the threshold of caterpillar vulnerability to the disease, allowing populations to grow denser without becoming more susceptible to infection.

The trees' own defenses（樹幹自衛）＝defoliation，然後raise＝increasing，

所以他是多跟少的差異，不是常跟短的差異，把他選起來就下課拉～～教師節快樂

選（Ｂ）（Ｃ）

以上筆記供大夥參考若有錯誤再煩請指教