FeiFei-81, FeiFei-75

wei_wangyan

大家来帮助偶一起进步逻辑好不好，刚才做了一组FF，好几道题都不怎么明白。谢谢！

81. Nuclear fusion is a process whereby the nuclei of atoms are joined, or “fused”, and in which energy is released. One of the by-products of fusion is helium-4 gas. A recent fusion experiment was conducted using “heavy” water contained in a sealed flask. The flask was, in turn, contained in an air-filled chamber designed to eliminate extraneous vibration. After the experiment, a measurable amount of helium-4 gas was found in the air of the chamber. The experiments cited this evidence in support of their conclusion that fusion had been achieved.

Which one of the following, if true, would cast doubt on the experimenters’ conclusion? 答案C

(A) Helium-4 was not the only gas founding the experiment chamber. 无关

(B) When fusion is achieved, it normally produces several by-products, including tritium and gamma rays. 无关

(C) The amount of helium-4 found in the chamber’s air did not exceed the amount of helium-4 that is found in ordinary air. 这个是怎么削弱的？不理解啊。

(D) Helium-4 gas rapidly breaks down, forming ordinary helium gas after a few hours.

(E) Nuclear fusion reactions are characterized by the release of large amount of heat.

75. Advertisers are often criticized for their unscrupulous manipulation of people’s tastes and wants. There is evidence, however, that some advertisers are motivated by moral as well as financial considerations. A particular publication decided to change its image from being a family newspaper to concentrating one sex and violence, thus appealing to a different readership. Some advertisers withdrew their advertisements from the publication, and this must have been because they morally disapproved of publishing salacious material.
Which one of the following, if true, would most strengthen the argument? 答案C

(A) The advertisers switched their advertisements to other family newspapers. FF详解上说这个选项“支持但不是最强”，还真有不够强这一说？问题中的most真起作用啊？这在GMAT题目中还没见过呢。谁能给出它不支持的原因？

(B) Some advertisers switched from family newspapers to advertise in the changed publication.

(C) The advertisers expected their product sales to increase if they stayed with the changed publication, but to decrease if they withdrew.

(D) People who generally read family newspapers are not likely to buy newspapers that concentrate on sex and violence.

(E) It was expected that the changed publication would appeal principally to those in a different income group.

（按照搜索格式，没有找到答案。）

[此贴子已经被作者于2006-12-6 23:09:49编辑过]

adpang

81 试验的结论是fusion发生了。而前提中提到fusion将产生一个副产品H－４。也就是说，如果结论是正确的，那么ｃｈａｍｂｅｒ里应该有ｆｕｓｉｏｎ产生的H－４。那么必然里面空气中ｈ－４的含量要高于外界的空气。（反映增加了ｈ－４的数量，那么也就增加了ｈ－４ｃｈａｍｂｅｒ里的浓度。）　选项说里面空气中ｈ的浓度跟外界一样，这样就说明没有新的ｈ产生。所以是ｗｅａｋｅｎ

adpang

７５　我把A选项的情况称之为需要二次假设的支持选项，也就是说选项也对原文进行支持，但还需要一个额外的假设条件。这个题的额外假设就是：“other family newspaper跟改变前的那家报社一样纯洁。”　如果有这个条件，A是完全的支持。试想，如果other family newspaper跟改变后的报社一样肮脏，那么就不是支持了。

wei_wangyan

谢谢adpang

思路很清楚，但总觉得对这里面“空气中含有helium-4”不十分理解，算是常识啊？

wei_wangyan

以下是引用adpang在2006-12-7 0:34:00的发言：
７５　我把A选项的情况称之为需要二次假设的支持选项，也就是说选项也对原文进行支持，但还需要一个额外的假设条件。这个题的额外假设就是：“other family newspaper跟改变前的那家报社一样纯洁。”　如果有这个条件，A是完全的支持。试想，如果other family newspaper跟改变后的报社一样肮脏，那么就不是支持了。

 

嗯，这个二次假设挺有道理。

谢谢。

sunnylbs

我也不明白：原文中明明已经说了" a measurable amount of H-4" 的存在了啊，C选项里这么说不是与原文矛盾么。。。。