[問題]GWD12-16

[sf_wang]

這題沒人問過，可是我一直想不通B選項

Certain genetically modified strains of maize produce a natural insecticide that protects against maize-eating insects. The insecticide occurs throughout the plant, including its pollen. Maize pollen is dispersed by the wind and often blows onto milkweed plants that grow near maize fields. Caterpillars of monarch butterflies feed exclusively on milkweed leaves. When, in experiments, these caterpillars were fed milkweed leaves dusted with pollen from modified maize plants, they died. Therefore, use of the modified maize inadvertently imperils monarch butterflies.

Which of the following, if true, most seriously weakens the argument?

A. Per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants.
B. Standard weed-control practices that have been used by farmers for decades have largely eliminated milkweed plants from certain areas where monarch-butterfly caterpillars were once common.
C. The experiments showed that the caterpillars were not harmed by contact with the pollen from the genetically modified plants unless they ingested it.
D. The maize-eating insects that the natural insecticide protects against do not feed on the pollen of the maize plant.
E. Airborne maize pollen tends to collect on the middle leaves of milkweed plants and monarch caterpillars feed only on the plant’s tender upper leaves.

答案是E，沒有問題

可是B為什麼不能weaken呢？
原文結論說 用改良過的玉米會造成蝴蝶的傷害
B說milkweed plants已經被從常有蝴蝶的地方eliminate了 --> 所以既使有害，也殺不到蝴蝶，原文的結論不成立。
這樣分析錯在哪裡啊？ 求助!!!!! 實在是想不通

[liwuu]

我想應該在於這一句certain areas where monarch-butterfly caterpillars were once common.
顯示這個control行為可能為時已晚或實際效果不大...

[evelight]

我認為B是無關選項
因為原文要找的是『改良過的玉米無法防治害蟲』
而B說某些地區使用傳統方法已經把大部分的害蟲都殺死了
可是我們不知道題目試驗的地區是否就是B裡面講的『某些地區』

[cocaine]

B是無關的
B只是說那些農夫的標準實施方式是怎樣做.
原文是要說明改良過的植物跟蝴蝶之間的關係..
你在體會看看...

[BECKY]

certain area 跟 were once common...都有點小瑕疵
在想一想喔....

[coruscant]

我認為B是無關選項
因為原文要找的是『改良過的玉米無法防治害蟲』
而B說某些地區使用傳統方法已經把大部分的害蟲都殺死了
可是我們不知道題目試驗的地區是否就是B裡面講的『某些地區』

我用我的方法補充一下好了:

題目是要證明改良方法其實不會殺死蝴蝶,B選項只講到農夫在某些地區用的方法會殺死毛毛蟲的唯一食物來源,充其量只能說明農夫的weed control practices是殺掉毛蟲的另一種方法,不能因為這樣就說modified strains of maize不具備殺毛蟲的能力,故B不充足

[schung0529]

[quote="sf_wang"]
Certain genetically modified strains of maize produce a natural insecticide that protects against maize-eating insects. The insecticide occurs throughout the plant, including its pollen. Maize pollen is dispersed by the wind and often blows onto milkweed plants that grow near maize fields. Caterpillars of monarch butterflies feed exclusively on milkweed leaves. When, in experiments, these caterpillars were fed milkweed leaves dusted with pollen from modified maize plants, they died. Therefore, use of the modified maize inadvertently imperils monarch butterflies.

Which of the following, if true, most seriously weakens the argument?

A. Per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants.
B. Standard weed-control practices that have been used by farmers for decades have largely eliminated milkweed plants from certain areas where monarch-butterfly caterpillars were once common.
C. The experiments showed that the caterpillars were not harmed by contact with the pollen from the genetically modified plants unless they ingested it.
D. The maize-eating insects that the natural insecticide protects against do not feed on the pollen of the maize plant.
E. Airborne maize pollen tends to collect on the middle leaves of milkweed plants and monarch caterpillars feed only on the plant’s tender upper leaves.

請問各位大大

為什麼C不行?

[維尼]

To schung0529

你要不要先說看看為什麼你覺得C可以?

[Lory]

Certain genetically modified strains of maize produce a natural insecticide that protects against maize-eating insects. The insecticide occurs throughout the plant, including its pollen. Maize pollen is dispersed by the wind and often blows onto milkweed plants that grow near maize fields. Caterpillars of monarch butterflies feed exclusively on milkweed leaves. When, in experiments, these caterpillars were fed milkweed leaves dusted with pollen from modified maize plants, they died. Therefore, use of the modified maize inadvertently imperils monarch butterflies.

Which of the following, if true, most seriously weakens the argument?

A. Per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants.
B. Standard weed-control practices that have been used by farmers for decades have largely eliminated milkweed plants from certain areas where monarch-butterfly caterpillars were once common.
C. The experiments showed that the caterpillars were not harmed by contact with the pollen from the genetically modified plants unless they ingested it.
D. The maize-eating insects that the natural insecticide protects against do not feed on the pollen of the maize plant.
E. Airborne maize pollen tends to collect on the middle leaves of milkweed plants and monarch caterpillars feed only on the plant’s tender upper leaves.

請問各位大大

為什麼C不行?

回答一下問題，C已經推翻題目囉!!!看紅色標記的地方吧!!!
既然caterpillars are fed by 該植物的leaves，of course, they will ingest them, right!!!!!

還有我覺得B不對的地方在於:
題目的中心在於是否因種植該改良品種的M植物會導致caterpillar死掉的原因，而B卻硬生生的把題目的立論點給改變了，也是推翻題目的一種選項，不如說是out of scope吧!!超出範圍的討論!!!
所以可以把BC一起想想喔!!!!!

[Miranda's]

我想應該在於這一句certain areas where monarch-butterfly caterpillars were once common.
顯示這個control行為可能為時已晚或實際效果不大...

支持這個論點，我覺得少了where monarch-butterfly caterpillars were once common. 這句，還是可以weaken 題目，因為計畫殺死了所有的milkweed，所以 maize的pollen不會傳播到milkweed上，因此也不會造成caterpillars死亡，很合理呀！ 所以我認為也不算是out of scope 的討 論
但是如果加上了
where monarch-butterfly caterpillars were once common.
這句，也就是說c全掛掉了，那於事無補，沒有用啦~
all above is my opinion, point out the mistakes if you can^^

[hccill]

請注意"certain area",這會造成樣本代表性不足, CR要求的是廣泛周延的證據喔!

[kaori110]

為什麼a不行呢
是因為主要WEAKEN是要WEAKEN不會危急蝴蝶嗎
(a) per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants

natural insecticide比其他chemical insecticide好-->不行weaken嗎
是因為less toxic不是重點嗎

[hughes0305]

a要weaken必需要有個前提是 "較少量的毒 不會使蝴蝶死亡",
但問題是　我們不知道毒性要多少才會危害到蝴蝶
換句話說　雖然此neutarl insecticide的毒較商用殺蟲濟較低了
但它很有可能還是"毒得足以殺死蝴蝶"!
因此　A並沒有weaken到原題的結論!

參考吧

[bonus]

E如何解釋？？？

[A級垂耳兔]

那些對蝴蝶幼蟲有毒的花粉傾向聚集在乳草葉中間
而蝴蝶幼蟲只吃那些聚集有毒花粉乳草葉上面的葉子
...就是不會吃到有毒的意思