小白求大神解答，问狒狒逻辑第12题为什么C 不对

青梅如豆

[size=1em]原题:12. The only physical factor preventing a human journey to Mars has been weight. Carrying enough fuel to propel a conventional spacecraft to Mars and back would make even the lightest craft too heavy to be launched from Earth. A device has recently been invented, however, that allows an otherwise conventional spacecraft to refill the craft’s fuel tanks with fuel manufactured from the Martian atmosphere for the return trip. Therefore, it is possible for people to go to Mars in a spacecraft that carries this device and then return. Which one of the following is an assumption on which the argument depends? (A) The amount of fuel needed for a spacecraft to return from Mars is the same as the amount of fuel needed to travel from Earth to Mars. (B) The fuel manufactured from the Martian atmosphere would not differ in composition from the fuel used to travel to Mars. (C) The device for manufacturing fuel from the Martian atmosphere would not take up any of the spaceship crew’s living space. (D) A conventional spacecraft equipped with the device would not be appreciably more expensive to construct than current spacecraft typically are. (E) The device for manufacturing fuel for the return to Earth weighs less than the tanks of fuel that a conventional spacecraft would otherwise need to carry from Earth for the return trip.

题主知道E项相关性更强，直接focus on 了weigh这个关键词，取非之后也能选出，但是C项要是取非也不觉得是不对的呀，也觉得可以选啊。而且该项不是也支持了这个方法的可行性吗，为什么不对呢？只是因为相关性没那么强吗。

青梅如豆

虽然问的很愚蠢，还是希望有好心的筒子们来解答一下呀

青梅如豆

顶起

cycgundam

GMAT的逻辑一般不推荐Make additional assumptions。直接能基于题目中给出的premise最好（也就是相关性强）。

来看看C：The device for manufacturing fuel from the Martian atmosphere would not take up any of the spaceship crew’s living space. 这个选项只是告诉你living space会被占用，但并没有告诉你占用多少，也没有告诉你占用了以后spaceship crew就不够了。所以客观上你并不清楚这个占用面积到底能不能影响飞行。为了让C可行，只有建立题目内容之外的额外假设和条件（比如这个device大到要占用90%的空间），而这对于gmat而言一般是不推荐的（某些极端题目倒是会有这些做正确选项）。

C的问题和B一样。B讲的不同的成分。但B并没有将成分不同会导致燃料不合格，题目也没讲燃料的成分必须是一种。所以这种看似“不同”其实对结论并不产生支持或削弱影响。

青梅如豆

cycgundam 发表于 2018-6-5 06:59
GMAT的逻辑一般不推荐Make additional assumptions。直接能基于题目中给出的premise最好（也就是相关性强） ...

哦哦哦哦好对！！有种茅塞顿开的感觉，好多时候做题都觉得选项有点相关然后就自己脑补起来，但是最后答案往往是最直接的那一个，原来问题出在这里！！谢谢大神啊