求助一道逻辑题~

笑脸多多1003 · 发表于 2010-4-28 23:40:22

求助~麻烦牛人指点下这道逻辑题
It has been hypothesized that much of the matter in the universe is "dark," i.e.,unseen.Studies have shown that galaxies in many galaxy clusters are moving faster with respect to one another than they would if visible stars constituted all their mass.The studies suggest that the galaxies are moving under the gravitational influence of unseen mass in considerable quantity.

Which of the following is an assumption underlying the passage above?

(C)the aggregate mass of visible stars in the galaxies mentioned above can be estimated with confidence.

这道题是陈向东逻辑第37页的一道题，我看了以后怎么也想不通为什么选C。感觉上都没什么关系~
麻烦哪位牛人能指点一下。太感谢了！

conniequan · 发表于 2010-4-29 16:08:30

有一片专门讲这个的阅读，不知道你都没读过，不过没关系啦
我是这样理解的：题干中说，visible stars提供的mass不足以让galaxies移动的那么快，所以肯定有其他invisible的mass在作用但是如果研究过程中低估了visible stars的mass呢？那么visible stars的mass有可能是足够使galaxies移动的那么快的，那么unseen mass的存在就得不到证实了
C选项假设说visible stars的mass是可以准确估测的所以正确

笑脸多多1003 · 发表于 2010-4-29 23:22:58

谢谢啦~~~~~~我当时一直想不通的是为什么stars的Mass要和galaxy的速度扯上关系，然后又开始想万有引力的关系，然后就越想越偏了~~~逻辑真的好难哦~~~

gracezz · 发表于 2010-4-30 11:19:10

其他的选项啥样？看来这题关键是读懂这句话：Studies have shown that galaxies in many galaxy clusters are moving faster with respect to one another than they would if visible stars constituted all their mass。如果只有visible 组成，那他们不会这么快，科学家由此推说肯定有dark物质。首要条件是他们对这些visible 的东西的质量估计是正确的。

笑脸多多1003 · 发表于 2010-4-30 22:04:42

A.measurements of the speed of moving galaxies are extremely unreliable
B.the workings of gravitational forces are not particularly well understood
C.the aggregate mass of visible stars in the galaxies mentioned above can be estimated with confidence.
D.the general compostion of unseen matter in the universe has been determined.
E.without exception,the galaxies mentiioned above move toward one another

求助一道逻辑题~

所属分类: GMAT考试

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