1 q in GWD-2-17

longxiaomeim

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?

1. When an olive oil is refined, the concentration of oleic acid in the oil is reduced.
2. The quality of an unrefined olive oil can be determined only by accurately measuring its acidity.
3. If an unrefined olive oil is intermediate in acidity between two other unrefined olive oils, it will also be intermediate between them in quality.
4. Free oleic acid is the only acid that unrefined olive oil contains. (C)
5. People who judge the quality of unrefined olive oils actually judge those oils by their acidity, which the judges can taste

Q: I chosed D. How to think over such CR problem? 3Q!

casualwalk

这题出的有问题。严格来说，没有一个对的。但比较下来，其他都错，只有a 不一定错。

题目说，未提炼的橄榄油并不能精确的由酸性定义。未提炼的橄榄油每升中free oleic 酸越少，油的质量越高。提炼后的橄榄油中free oleic 酸的量可以精确定义这个油的酸性。

这里有个陷阱，前面提到油都有unrefined修饰，唯独最后这个没有，也就是暗示了是提炼后。真是太狡猾了。那么我们就知道它其实是在说，提纯前，橄榄油里有很多酸（包括free oleic 酸),提纯后，其他酸都被去除了，free oleic 酸要么很难完全去除干净，要么根本不会被去除。

B，C， D都在说unrefined橄榄油和酸性之间的问题，原文第一句话就否定了一切。所以，只剩a 了。

不知道真实题目会不会有变，我想真实题目的答案应该会聚焦于提炼后的情况。

grasses

I thought the word of "only" is worth serious attention,  as B, D, the above information did not give any suggestion of "only", so the two items could be precluded. Based on " the less blah blah,  higher blah balh.. " I found C is the only answer deductive from the given information.

kenlily

What the text talks bout is that the oleic acid has been proved helpful in measuring the quality of unrefined olive oil although it is not actually defined to do so. The text does not provide us with anything about whether the above-mentionned acid is the only acid that can be found in unrefined olive oil, so choice D cannot be true. Besides, as an answer to CR question, choice D is a little bit too absolute to be a correct one.