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cournot

Q14lantings of cotton bioengineered to produce its own insecticide against bollworms, a major cause of crop failure, sustained little bollworm damage until this year.  This year the plantings are being seriously damaged by bollworms.  Bollworms, however, are not necessarily developing resistance to the cotton’s insecticide.  Bollworms breed on corn, and last year more corn than usual was planted throughout cotton-growing regions.  So it is likely that the cotton is simply being overwhelmed by corn-bred bollworms.

In evaluating the argument, which of the following would it be most useful to establish?

1. Whether corn could be bioengineered to produce the insecticide

2. Whether plantings of cotton that does not produce the insecticide are suffering unusually extensive damage from bollworms this year

3. Whether other crops that have been bioengineered to produce their own insecticide successfully resist the pests against which the insecticide was to protect them

4. Whether plantings of bioengineered cotton are frequently damaged by insect pests other than bollworms

5. Whether there are insecticides that can be used against bollworms that have developed resistance to the insecticide produced by the bioengineered cotton

ｔｈｅ　ａｎｓｗｅｒ　ｉｓ　Ｂ，ｗｈｙ　ｎｏｔ　Ａ？

gonghao

题目说。

生物改造后的棉花能自己产生杀虫剂，且直到去年一直有很低的B虫的感染率。

但是去年被B虫的弄坏的棉花多了。B虫吃的是谷物，去年谷物种植多。结论说：棉花只是因为B虫多才坏的多。

问评价：

谷物多－－B虫子多－－－破坏多。

如果是简单的结论的话，杀虫剂其实应该是没啥作用的。

如果不是这样简单的结论的话，杀虫剂应该是起作用的。

B说评价自己不产杀虫剂的植物的破坏情况怎么样

如果说是和产杀虫剂的植物一样，则说明就是应为虫多

如果说比产杀虫剂的植物要少

那就说明有其它原因使得棉花产量变少了。

A谷物是否产杀虫剂和棉花的大量减少没有什么关系

cournot

我是这么想的：

生物改造后的棉花能自己产生杀虫剂，且直到去年一直有很低的B虫的感染率。

但是去年被B虫弄坏的棉花多了。B虫是吃corn长大，去年在棉花地附近种了很多corn。

结论说：棉花破坏是因为corn多，B虫多，所以破坏多。

A 如果corn能自己产生杀虫剂，那么就说明corn多B虫不会多（至少在棉花和corn地区B虫不多）；

B 不产杀虫剂的棉花破坏程度？=>焦点就在杀虫剂是否有效，但是题中明明说杀虫剂有效并且B虫不会有抵抗杀虫剂的免疫能力

gonghao

corn产不产杀虫剂在题目中没有提及

题目中说的是一对矛盾：一边是杀虫剂曾经保护了棉花，一边是去年一下子冒出来很多虫子，且棉花被破坏

如果是杀虫剂的原因，这样的破坏是不应该出现的。所以这是一对矛盾。

如果是【产】和【不产】杀虫剂的棉花都遭到大量的破坏的话，那就说明【杀虫剂】对于破坏没有意义。

bluetea

同意gonghao，补充一点，题目给两个因素：（1）杀虫剂失效（2）B虫数量多，答案只需有利于排除一个就好。

B的意思是，都是棉花，一个有杀虫剂，一个没有杀虫剂，如果一样被吃，杀虫剂没效果；如果被吃的数量不一样（没杀虫剂的被吃的多），证明杀虫剂有效果，因此排除其中一个因素。

这类逻辑题，我认为，真TMD变态，如果你一直想着题目的内容，你肯定找不到，但是如果你只是从原文提炼两个因素，找排除其中一个因素的答案，就好找。

其实这个题，答案就和一句话有关系：Bollworms, however, are not necessarily developing resistance to the cotton’s insecticide.

[此贴子已经被作者于2006-7-20 4:20:07编辑过]

mymengming

以下是引用gonghao在2006-7-4 8:52:00的发言：

corn产不产杀虫剂在题目中没有提及

题目中说的是一对矛盾：一边是杀虫剂曾经保护了棉花，一边是去年一下子冒出来很多虫子，且棉花被破坏

如果是杀虫剂的原因，这样的破坏是不应该出现的。所以这是一对矛盾。

如果是【产】和【不产】杀虫剂的棉花都遭到大量的破坏的话，那就说明【杀虫剂】对于破坏没有意义。

版主理解题目错误,文章问的是是不是玉米里的虫子害了棉花,不是产量的多少.

应该是B

gator21

ding

gonghao

to mymengming

之前的理解确实有误，结论it is likely that the cotton is simply being overwhelmed by corn-bred bollworms.说是玉米虫太多了，原因是去年种棉花的地上中上了玉米，使得棉花遭殃

问题是，是不是玉米虫惹得祸呢？

看看B，没有杀虫剂的棉花怎么样，如果没破坏，那就对了。如果有破坏，说明这些虫子不单吃玉米，也吃棉花，只要没有棉花自己产生的杀虫剂，虫子都吃，那么结论就不对了。

[此贴子已经被作者于2007-7-14 23:55:06编辑过]

MaccMichAA

...

smileday

the issue offers two reasons for us to evaluate which one is the more possible cause for the unexpected damage of the engineered cotton: 

1. Bollworms has developed resistance to the inseciticide, or

2. simply overwhelmed by a lot of bollworms as a result of a lot of corn.

yet, the argument refuted the first reason, so, the second one is the argument's position: the cotton damage is due to a lot of bollworms, not the unkept inseciticide resistance of Bollworms.

i think that choice B is out of scope ( cotton without insecticide is not the issue in question), and couldn't be the best choice.

instead, A is preferred. (if corn could be engineered to produce the insecticide as well, Bollworms would not be numerous; then, the argument's position is weakened.) 

open to discuss...

 

[此贴子已经被作者于2006-10-25 9:45:10编辑过]