请教OG13 SC107

琛angela

107. While it costs about the same to run nuclear plants as other types of power plants, it is the fixed costs that stem from building nuclear plants that makes it more expensive for them to generate electricity.
(A) While it costs about the same to run nuclear plants as other types of power plants, it is the fixed costs that stem from building nuclear plants that makes it more expensive for them to
generate electricity.
(B) While the cost of running nuclear plants is about the same as for other types of power plants, the fixed costs that stem from building nuclear plants make the electricity they generate more expensive.
(C) Even though it costs about the same to run nuclear plants as for other types of power plants, it is the fixed costs that stem from building nuclear plants that makes the electricity they generate more expensive.
(D) It costs about the same to run nuclear plants as for other types of power plants, whereas the electricity they generate is more expensive, stemmingfrom the fixed costs of building nuclear plants.
(E) The cost of running nuclear plants is about the same as other types of power plants, but the electricity they generate is made more expensive because of the fixed costs stemming from building nuclear plants.


B选项中的for是什么意思？为什么不能删掉？谢谢！

curtis0063

这题的 preposition 用法挺少见的，我对preposition 还不甚熟练，仅以手头上的资料来判断。

For: 一般当 preposition 用，指特定的目的或与特定的字连用成片prepositional phrase.
牛津字典对 for 的解释: http://oxforddictionaries.com/definition/american_english/for?region=us&q=for

As: 当conjunction 有三种用法，Duration (= while, during); Causation (=since, because); Comparison (= in the same way)
  当preposition 一样三种用法, Function; Equation; Stage
     (详细请参考Manhattan GMAT Sentence Correction 4th edition – P.255)
  依题意same as 当作比较来用所以应为conjunction 用法。

我从 GMAT CLUB 找到别人的解释，(A) 和 (E) 若是没有for 则句意变成：
The costs of running nuclear plants are compared with other types of plants.

原题是要比较两种“cost” 而不是“cost” 比“other types of power plants”。我解释得不是很好，OG 也没讲清楚，所以我也是在等其他高手解答

whzyc1990

借楼同问，为什么强调句型在这里用不了呢，什么叫good reason？

renco

for是界定比较对象，有了for，as前后比较的就是核电站的运营成本和其他种类电站的“情况”，for就是要带出这个情况来，没有for的话，就是核电站的运营成本和其他种类电站本身来比较，完全没有逻辑。

babybearmm

ls说得很对，我觉得"for"就是去“意会”的，that makes sense! 本身GMAT SC强调的就是句意逻辑。所以不妨多读这个正确句子，去体会意思哈


lz可以看看这道题，是"for ..."，很类似：
http://forum.chasedream.com/GMAT_SC/thread-740963-1-1.html

daisynidongwei

多谢啦！