求助PREP1-27 BF题~~感谢回答！~

水色青空

27.(31231-!-item-!-188;#058&004411)

Plant scientists have used genetic engineering on seeds to produce crop plants that are highly resistant to insect damage.Unfortunately, the seeds themselves are quite expensive, and the plants require more fertilizer and water to grow well than normal ones.Thus, for most farmers the savings on pesticides would not compensate for the higher seed costs and the cost of additional fertilizer.However, since consumer demand for grains, fruits, and vegetables grown without the use of pesticides continues to rise, the use of genetically engineered seeds of this kind is likely to become widespread.

In the argument given, the two portions in boldface play which of the following roles?

(A) The first supplies a context for the argument; the second is the argument's main conclusion.

(B) The first introduces a development that the argument predicts will have a certain outcome; the second is a state of affairs that the argument denies will be part of that outcome.

(C) The first presents a development that the argument predicts will have a certain outcome; the second acknowledges a consideration that weighs against that prediction.

(D) The first provides evidence to support a prediction that the argument seeks to defend; the second is that prediction.

(E) The first and the second each provide evidence to support the argument's main conclusion.

额，一开始就选了A，觉得那个CONTEXT很合适，但是答案是C~~不知道该怎么解释？希望NN帮帮忙~~谢谢了！

keerbaobei

顶~~~好久没看过g，已经完全忘记了……姐姐，你这么早又复习了？呵呵，加油！！！

ellie78

一不小心蒙对了...不是牛人，但是也讲一下鄙人的思路，楼主凑合听哈~

段落结构是这样的：先说此物的缺点，后面再讲因为其他方面的因素，还是要肯定它。前BF讲缺点，后BF讲优点。后面是main conclusion.前BF将小非，后BF讲大是。

到这里先把DE排除了。D一出现prediction我就觉得不用看内容了，E用and连接1st和2nd，将两者共性，看着结构就知道后面说不出正确的话。甭看了。

A说前BF是context，不对，context一般是讲语境，铺垫主观点，所以态度上应该跟观点站在一条战线，一是一非肯定不行

B说后BF否定了前BF的部分outcome--不对，后者提的是比前者更大局的“是”，而没有在“非”的基础上再次否定

所以，C

盼真正大牛拍砖~

---又重新编辑了一下，按照C解释的，错写成了B，汗...

catherine66

我也选的A

lovepiao

第二句黑体字开头有However。所以第一句为文章反对的观点，第二句为文章的结论
A: The first supplies a context for the argument错，应该是文章反对的
B:说反了
C: weighs against正好说明了反对，对应了however
D: The first provides evidence to support a prediction that the argument seeks to defend错，应该是文章反对的，而不是defend
E:错。同理，第一句是文章反对的观点，而第二句是文章的main conclusion，而不是evidence to support the argument's main conclusion

aomeisoft7

第二句黑体字开头有However。所以第一句为文章反对的观点，第二句为文章的结论
A: The first supplies a context for the argument错，应该是文章反对的
B:说反了
C: weighs against正好说明了反对，对应了however
D: The first provides evidence to support a prediction that the argument seeks to defend错，应该是文章反对的，而不是defend
E:错。同理，第一句是文章反对的观点，而第二句是文章的main conclusion，而不是evidence to support the argument's main conclusion

-- by 会员 lovepiao (2010/4/21 20:47:45)

我对A的分析有看法
B1说是施肥和浇水会要更多的成本，作者并没有反对这一点，B2说，因为消费者需求会增长（其言下之意是，施肥和浇水的成本是比原来多，但是需求增长带来的利益会弥补这一成本使农民受益），所以还是要种。
B2中however反对的是thus后面的观点（即农民不会去种），而不是反对的B1中说到的施肥和浇水成本高的观点。
求高人解答！！

mongmong

ls所言极是，C选项里weigh against恰好说明了优势劣势的比较

GMAT008

还有人讨论吗？疑惑ing,今天做到了此题，说说我的推理，请大牛帮着分析一下：

题意：
1. PS研发了GE的S可以抗虫但是贵，而且还需要更多的FW才能长得好-->农夫种GE的S不省钱-->所以很难推广开；
2. 因为有特殊人群保证了GE的S的需求，所以S还是很可能普及开的。

BF1是第一层结论的论据，但可以说引起了整个论证；
BF2则是直接反对了第一层结论并给出了主结论。

所以我到现在还是觉得A有合理性。

Ericli9

这个问题我一开始也选了A，后来参考**上的讨论以及manhattan上Ron的解释，觉得还是C更好。
GMAT中的context只是作为背景信息，不直接参与到argument的前提->结论的推理过程当中。这样的话，A的前半句是不对的，排除掉。
整段的结构如下：
Plant scientists have used genetic engineering on seeds to produce crop plants that are highly resistant to insect damage. (Context)
Unfortunately, the seeds themselves are quite expensive, and the plants require more fertilizer and water to grow well than normal ones. (Fact 1 to support prediction 1)
Thus, for most farmers the savings on pesticides would not compensate for the higher seed costs and the cost of additional fertilizer. (Prediction 1)
However, since consumer demand for grains, fruits, and vegetables grown without the use of pesticides continues to rise, the use of genetically engineered seeds of this kind is likely to become widespread. (Fact 2 to support Prediction 2 -> Main conclusion)

奥兰多铁杆球迷

我也选了A，但后来看了下答案的解释，仿佛C更合理。尤其是那个however = weigh against