求助：一道阅读题

songxiaoshiUID：3170134

Upwards of a billion stars in our galaxy have burnt up their internal energy sources, and so can no longer produce the heat a star needs to oppose the inward force of gravity. These stars, of more than a few solar masses, evolve, in general, much more rapidly than does a star like the Sun. Moreover, it is just these more massive stars whose collapse does not halt at intermediate stages (that is, as white dwarfs or neutron stars). Instead, the collapse continues until a singularity (an infinitely dense concentration of matter) is reached.
It would be wonderful to observe a singularity and obtain direct evidence of the undoubtedly bizarre phenomena that occur near one. Unfortunately in most cases a distant observer cannot see the singularity; outgoing light rays are dragged back by gravity so forcefully that even if they could start out (start out: v.出发, 动身) within a few kilometers of the singularity, they would end up (end up: v.竖着, 结束, 死) in the singularity itself.



26.
The passage suggests which of the following about the Sun?
I.
The Sun could evolve to a stage of collapse that is less dense than a singularity.
II.
In the Sun, the inward force of gravity is balanced by the generation of heat.
III.
The Sun emits more observable light than does a white dwarf or a neutron star.
(A) I only
(B) III only
(C) I and II only
(D) II and III only（C）
(E) I, II, and III
这个2说balance是根据下面这句么，也没提到balance啊？？
utgoing light rays are dragged back by gravity so forcefully that even if they could start out (start out: v.出发, 动身) within a few kilometers of the singularity, they would end up (end up: v.竖着, 结束, 死) in the singularity itself.


3为什么不对呢，是因为没给出白矮星的情况所以无法比较？？
1其实我也不大理解？是说太阳变得速度慢，所以不能变成singularity？？


谢谢，应该有人做过这个题把！！求高人指点

dingda6UID：3189688

1的根据在第一段，作者的推理是evolve的速度是根据mass，所以more massive evolve more rapidly,以至于它们不会停留在intermediate stage,而直奔singularity。既然太阳没有这么多的mass，最终的collapse也less dense than a singularity.
2的根据是第一句：Upwards of a billion stars in our galaxy have burnt up their internal energy sources, and so can no longer produce the heat a star needs to oppose the inward force of gravity.
这句说stars要burn up their internal energy sources，balance就会被打破。而太阳是没有burn up internal energy sources的（其实这里我觉得这篇文章也没有给明条件，要这样推理的话只能说是作者默认大家是知道的），所以太阳是balance的。
3是没有给明的，文章的最后一句只是解释了为什么我们几乎不能观察到singularity的原因，即质量太大而将光束缚，而没有提供关于白矮星和中子星的束缚光的信息，所以3是属于无中生有的。

echozwwUID：3241695

楼上说的挺好，不过我觉得第二个问题，题目中也是有给出的。
第一句：Upwards of a billion stars in our galaxy have burnt up their internal energy sources, and so can no longer produce the heat a star needs to oppose the inward force of gravity。是说这些stars通过burnt up their internal energy sources来平衡the inward force of gravity；
然后下面一句These stars, of more than a few solar masses, evolve, in general, much more rapidly than does a star like the Sun。这一句中开始是用these stars 后面又说了a star like sun，不就是说sun也是其中之一嘛，那他也应该具有同样的性质。

xiduchongyangUID：2694716

奇点的密度是无限大的吧。所以第一个就对了。

these stars 是说第一句那些会耗尽的，紧着说，这些东西 much more rapidly than does a star like the Sun，所以应该可以取非。就死会平衡。。

另外，楼主，这篇文章的两段之间是承接关系，第二段根本没有提到太阳。

如果您找对应找到了第二段，应该是对文章琢磨的不透。哎，我有时候短文章全错。。。。。

一起加油~~~~

lansir002UID：3125688

用排除法做这道题的人掩面路过啊（2是对的，3是新信息），然后排除= = 鄙视我吧

songxiaoshiUID：3170134

2# dingda6 O(∩_∩)O谢谢！

songxiaoshiUID：3170134

3# echozww O(∩_∩)O谢谢！一起加油！

songxiaoshiUID：3170134

4# xiduchongyang O(∩_∩)O谢谢！一起加油！

songxiaoshiUID：3170134

5# lansir002 O(∩_∩)O谢谢！一起加油！

songxiaoshiUID：3170134

谢谢楼上各位！
楼主总结一下：
1.根据第一段的solar masses和Moreover, it is just these more massive stars whose collapse does not halt at intermediate stages (that is, as white dwarfs or neutron stars). Instead, the collapse continues until a singularity (an infinitely dense concentration of matter) is reached.
知道more solar masses的才会变成singularity，所以取非得A正确
2.根据第一段第一句（突然跳到第一句了orz）Upwards of a billion stars in our galaxy have burnt up their internal energy sources, and so can no longer produce the heat a star needs to oppose the inward force of gravity.  
这个oppose 大概有balance 的含义。
3.无中生有。
p.s.其实五楼的兄弟说得很对2,3就可以判断出来了.