一道6/18考到过的题目，讨论过但没有定论，恳请mindfree等大侠出山指点

ReedSong

The quality of unrefined olive oil is not actually defined in terms of acidity, yet extensive tests have shown that the less free oleic acid an unrefined olive oil contains per liter, the higher its quality.  The proportion of free oleic acid that an olive oil contains is an accurate measure of the oil’s acidity.

If the statements above are all true, which of the following conclusions is best supported by them?

When an olive oil is refined, the concentration of oleic acid in the oil is reduced.

The quality of an unrefined olive oil can be determined only by accurately measuring its acidity.

If an unrefined olive oil is intermediate in acidity between two other unrefined olive oils, it will also be intermediate between them in quality.

Free oleic acid is the only acid that unrefined olive oil contains.

People who judge the quality of unrefined olive oils actually judge those oils by their acidity, which the judges can taste.

这道题目前面已经讨论过了，但还是没有定论：

http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=508166&id=56858&skin=0

请各位高手不吝指教！

小样

不是讨论出来了吗？c阿

tulipmontreal

C

lawyer_1

A，见楼主衔接中本人的详细分析

cranberry

我认为A不是一个好的答案，首先，我认为文中后来出现的“olive oil”并不是指精炼后的橄榄油，因为如果是的话，文章的意思如下“未经提纯的橄榄油的质量实际上不是通过其酸度来确定的，然而，广泛的试验表明，每升未提纯的橄榄油所含的游离油酸越少，其质量越高。精炼橄榄油所含的游离油酸是衡量其酸度的准确标准。”这样，我们遇到的第一个问题是，未经提纯的橄榄油的酸度和其游离油酸的含量之间没有明确的关系了。第二个问题是，精炼橄榄油的精炼过程对未精炼橄榄油的效果是什么。第三个问题，我们不知道提纯后的橄榄油是酸性增加还是减少，理由是对未经提纯橄榄油的质量的定义未必同于对精炼橄榄油的质量的要求。也就是说，未经精炼的橄榄油是质量越高，游离油酸含量越少，但对精炼橄榄油呢，这是未定的。如果A是答案，我们需要一个非常重要的假设，即精炼橄榄油比未精炼的橄榄油的酸度降低。但这个我们从文章中看不到，如果把许多文章中看不到的信息加入到推理中，那和题目的要求就不合了。我的理解是，最后一句仅仅是建立起一个联系，即橄榄油中游离油酸的含量和其酸度是确定相关的。由此，酸度和质量也建立了联系。得到答案C。

bigbeard

当然是c。A肯定错。

文中根本就没提到精炼前后的变化。结论中的橄榄油质量，也没有明确指明是精炼后的橄榄油的质量。无法支持A。

lawyer_1

to cranberry

你的第一个问题：原文说未提炼橄榄油的游离油酸越少，其质量越高。说明关系是明确的（THE LESS。。。 THE HIGHER是比较关系，一个高，则一个低。一个低，则一个高），只是没说定量关系。这程意思（定量关系）推理中用不上。只要能推到：可以用游离油酸多少去衡量质量。则可以

你的第二个问题：无关。提炼过程酸性减少也是推出来的。其他变化无关

你的第三个问题：虽然未提炼橄榄油和提炼橄榄油的质量定义可能不同。但推理不需要他们相同。只要知道游离油酸对提炼橄榄油不是好东西就可以。而从好的未提炼橄榄油含游离油酸少推出游离油酸对提炼橄榄油不是好东西，这个推理是合适的。未提炼橄榄油的价值在提炼橄榄油，从定性来说，他的质量好坏应和提炼橄榄油（提炼后的东西，人们也是用提炼后的东西）挂钩。

你所说的需要的重要假设这是A要说的，因为提炼橄榄油的酸度就是游离油酸的含量。而提炼过程酸性减少。

详细推理见楼主衔接中本人的详细分析

TO BE DISCUSSED

mindfree

C. Based on the argument, acidity should also indicate theconcentration of O acid.  For example, based on the question,higher O acid indicates higher acidity. Therefore, when acidity ishigh, the O acid concentration is high because these two go hand inhand. Each is a required and sufficient condition for the other. Then Ccan be safely concluded to be true.

A cannot be correct. To reach such conclusion, one has to useinformation beyond what is given in the argument. It is strictlyforbidden in CR. Nowhere in the argument refined oil is mentioned andthere is no such information that same rule (less O acid --> higherquality) also applies to refined oil. We do not even know whetherrefined oil is higher in quality than unrefined or not. For example,refined oil might simply not have some harmful content that exists inunrefined.

lawyer_1

原文是推不出未提炼橄榄油的ACIDITY就是游离油酸的浓度，或者说由游离油酸的浓度决定其酸度。这就是C最关键之处。注意到原文最后一句话并不是指未提炼橄榄油，而是提炼后的橄榄油。

[此贴子已经被作者于2004-7-7 1:19:48编辑过]

mindfree

Lawyer,

I have to disagree with either assertion above.

The argument says that O acid is an accurate measure of theacidity. I conclude that they go hand in hand. For example:AÓãÑÀ³ÝµÄÊýÁ¿µÄ¶àÉÙºâÁ¿AÓãµÄÄêÁä¡£Èç¹ûijÌõAÓãÑÀ³Ý¶à£¬ËµÃ÷ÄêÁä¸ß¡£Í¬Ê±Èç¹ûijÌõAÓãÄêÁä´ó£¬ÆäÑÀ±Ø¶à¡£

The last sentence does not refer particularly to refined oil. I do notread refined oil in the whole paragraph. At most it refers to bothrefined and unrefined, thus applying to both.