LSAT-20-2-13

valarie

13.     Astronomers have long thought that the irregularity in the orbit of the planet Neptune was adequately explained by the gravitational pull exerted on Neptune by the planet Pluto. The most recent observations of Pluto, however indicate that this planet is much too small to exert the amount of gravitational pull on Neptune that astronomers once thought it did.

If the statements above are true, they provide the most support for which one of the following?

(A) Neptune is somewhat larger than scientists once believed it to be.

(B) The orbit of Neptune is considerably more irregular than scientists once thought it was.

(C) There exists another, as yet undiscovered, planet with an orbit beyond that of Pluto.

(D) The gravitational pull of Pluto is not the sole cause of Neptune’s irregular orbit.（D）

(E) Further observations of Pluto will eventually show it to be even smaller than it is now thought to be.

D is the answser. C 中 planet with an orbit beyond that of Pluto 是什么意思？

lugubrious

觉得在冥王星外还有一个星.(绕着太阳转的第10颗)

valarie

那是不是也可以作为答案？还有一颗星提供先引力所以N 's orbit is irregular?

lugubrious

不能，因为整个陈述里，没有提到这个问题。

这只是一个你自己可以做的猜想。并用到了，题目中以外得信息。

你只能根据陈述得问题，作出每个人都能接受的，客观的结论。不能有你主观的想象。

valarie

what if C is "There exists another, as yet undiscovered, planet that exerts the amount of gravitational pull on Neptune " , is C the answer? When I did this question, I ungrounded thought this way.

lawyer_1

1。严格讲不行，说不定是其它东东（非PLANET）产生对N星的 gravitational pull 。答案只能推到有别的力使N轨道不规则，至于是什麽产生这个别的力，就不知道了，不一定是PLANET。

2。C的意思为：存在别的PLANET，其轨道在P星的轨道之外。这有两个错误，一是如1所讲，只能知道有别的力，不知道这个别的就是PLANET。二是有别的轨道，即有别的星，不一定有这个引力使N星偏离轨道，就像P星。