Reading Comprehension
试题详情
文章：
| Line | After evidence was obtained in the 1920s that |
| the universe is expanding, it became reasonable to | |
| ask: Will the universe continue to expand | |
| indefinitely, or is there enough mass in it for the | |
| (5) | mutual attraction of its constituents to bring this |
| expansion to a halt? It can be calculated that the | |
| critical density of matter needed to brake the | |
| expansion and “close” the universe is equivalent | |
| to three hydrogen atoms per cubic meter. But the | |
| (10) | density of the observable universe—luminous |
| matter in the form of galaxies—comes to only a | |
| fraction of this. If the expansion of the universe is | |
| to stop, there must be enough invisible matter in | |
| the universe to exceed the luminous matter in | |
| (15) | density by a factor of roughly 70. |
| Our contribution to the search for this “missing | |
| matter” has been to study the rotational velocity of | |
| galaxies at various distances from their center of | |
| rotation. It has been known for some time that | |
| (20) | outside the bright nucleus of a typical spiral galaxy |
| luminosity falls off rapidly with distance from the | |
| center. If luminosity were a true indicator of mass, | |
| most of the mass would be concentrated toward | |
| the center. Outside the nucleus the rotational | |
| (25) | velocity would decrease geometrically with |
| distance from the center, in conformity with | |
| Kepler’s law. Instead we have found that the | |
| rotational velocity in spiral galaxies either remains | |
| constant with increasing distance from the center | |
| (30) | or increases slightly. This unexpected result |
| indicates that the falloff in luminous mass with | |
| distance from the center is balanced by an | |
| increase in nonluminous mass. | |
| Our findings suggest that as much as 90 percent | |
| (35) | of the mass of the universe is not radiating at any |
| wavelength with enough intensity to be detected | |
| on the Earth. Such dark matter could be in the | |
| form of extremely dim stars of low mass, of large | |
| planets like Jupiter, or of black holes, either small | |
| (40) | or massive. While it has not yet been determined |
| whether this mass is sufficient to close the universe, | |
| some physicists consider it significant that estimates | |
| are converging on the critical value. |
题目：
The authors’ suggestion that “as much as 90 percent of the mass of the universe is not radiating at any wavelength with enough intensity to be detected on the Earth” (lines 34–37) would be most weakened if which of the following were discovered to be true?
选项:
A、Spiral galaxies are less common than types of galaxies that contain little nonluminous matter.
B、Luminous and nonluminous matter are composed of the same basic elements.
C、The bright nucleus of a typical spiral galaxy also contains some nonluminous matter.
D、The density of the observable universe is greater than most previous estimates have suggested.
E、Some galaxies do not rotate or rotate too slowly for their rotational velocity to be measured.
答案:
A
提问：
我错选D，上来就把A杀了。这道题反映出来我细节逻辑定位还是不行，考场上加上紧张很容易失去耐心思路更乱。麻烦您帮我顺下思路及提一些建议，我多练练再。感谢！
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提问：
能否请您分析一下全文的结构以及最后一段的作用，最后一段并不是很理解觉得应该是问题答案尚且不能确定的意思，读了最后一段的第一句和第二句（第二句是对第一句的解释？）确定BE是不对的，在cd中选了C，不清楚A是如何驳斥原文的。谢谢老师~
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提问：
这个题如何定位呢。文章说our findings suggest that，我就到第二段去找，但是不知道应该定位到第二段具体哪里，这个定位的思路是怎么样的 ？
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