首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers.
In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers.
admin
2019-11-17
83
问题
In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers. Possibly as numerous as conventional galaxies, these galaxies have the same general shape and even the same approximate number of stars as a common type of conventional galaxy, the spiral, but tend to be much larger. Because these galaxies’ mass is spread out over larger areas, they have far fewer stars per unit volume than do conventional galaxies. Apparently these low-surface-brightness galaxies, as they are called, take much longer than conventional galaxies to condense their primordial gas and convert it to stars—that is, they evolve much more slowly.
These galaxies may constitute an answer to the long-standing puzzle of the missing baryonic mass in the universe. Baryons—subatomic particles that are generally protons or neutrons—are the source of stellar, and therefore galactic, luminosity, and so their numbers can be estimated based on how luminous galaxies are. However, the amount of helium in the universe, as measured by spectroscopy, suggests that there are far more baryons in the universe than estimates based on galactic luminosity indicate. Astronomers have long speculated that the missing baryonic mass might eventually be discovered in intergalactic space or as some large population of galaxies that are difficult to detect.
The primary purpose of the passage is to
选项
A、describe a phenomenon and consider its scientific significance
B、contrast two phenomena and discuss a puzz ing difference between them
C、identify a newly discovered phenomenon anc explain its origins
D、compare two classes of objects and discuss the physical properties of each
E、discuss a discovery and point out its inconsistency with existing theory
答案
A
解析
Main idea
This question requires understanding, in broad terms, the purpose of the passage as a whole. The first paragraph describes a phenomenon: the discovery of dim galaxies and some of their general attributes. The second paragraph describes how this discovery may help astronomers to solve a long-standing puzzle about the baryonic mass of the universe.
A Correct. The passage describes the phenomenon of dim galaxies and describes their significance in solving the longstanding puzzle of the missing baryonic mass in the universe.
B Although the passage discusses the puzzling difference between the two estimates of baryonic mass, this option does not account for the broader topic of dim galaxies.
C While the passage identifies the newly discovered phenomenon of dim galaxies, it does not offer a significant explanation for these galaxies’ origins.
D Although the passage compares dim an 1 conventional galaxies in the first paragraph, this option does not account for the important detail that dim galaxies may help solve a long-standing puzzle.
E The discovery of dim galaxies discussed in the passage is not said to be inconsistent with any existing scientific theory.
The correct answer is A.
转载请注明原文地址:https://kaotiyun.com/show/ULkO777K
本试题收录于:
GMAT VERBAL题库GMAT分类
0
GMAT VERBAL
GMAT
相关试题推荐
LivinginthecentralAmericandeserthasitsproblems,________obtainingwaterisnottheleast.
Itwasnot______1982thathewentbacktoAmerica.
Treesareusefultomaninthreeimportantways:theyprovidehimwithwoodandotherproducts;theygivehimshade;andtheyhe
Extensivenewstudiessuggestthatdieworldhasmadeextraordinaryprogressinreducingpovertyinrecentdecades.Theresearch
Scientistssaidtheyhavefoundevidenceofagiantplanetfaroutinoursolarsystem.Inastatement,theCaliforniaInstitute
SpeakerA:So,what’sthestatusofouradvertisingcampaign?SpeakerB:AsImentionedbefore,it’llbeanationalcampaignsta
AstheTitanicwassinkingandwomenandchildrenclimbedintolifeboats,themusiciansfromtheship’sbandstoodandplayed.T
ItusedtodistresslargenumbersofEasternpeopleswholivedmainlyonrice.
Whenwe’relearningaforeignlanguage,makingsenseofwhatwehearisthefirststeptowardfluency.Itsoundsobvious,butun
Accordingtotheauthor,abornnaturalistshouldfirstofallbe______.Theauthorcan’trememberhisrelativesclearlybecaus
随机试题
高繚仕于晏子,晏子逐之。左右辣日:“高繚之事夫子三年,曾無以爵位而逐之,其義可乎?”晏子日:“婴仄陋之人也,四維之然後能直。今此子事吾三年,未嘗弼吾遏,是以逐之也。”今此子事吾三年,未嘗弼吾過,是以逐之也。
向不特定对象公开发行的证券票面总值超过一定数额的,应当由承销团承销,这个数额是人民币()
下列关于清算企业分配剩余财产表述正确的有()
脱髓鞘疾病病理过程中的具有特征性的表现是
自动冲洗显影液中加入坚膜剂的作用是()。
某宗已抵押的收益性房地产,年有效毛租金收入500万元,年房屋折旧费30万元,维修费、保险费、管理费等50万元,水电供暖费等40万元,营业税及房地产税等65万元,年抵押贷款还本付息额70万元,租赁合同约定,保证合法、安全、正常使用所需的一切费用均由出租人负担
下列对于建设期利息概念的表述,正确的是()。
中国公民王某就职于国内A上市公司,2014年收入情况如下:(1)1月1日起将其位于市区的一套公寓住房按市价出租,每月收取租金3800元。1月因卫生间漏水发生修缮费用1200元,已取得合法有效的支出凭证。(2)在国内另一家公司担任独立董事,3月取得该公司
建立国际政治经济新秩序的基础是()。
“没有革命的理论,就没有革命的运动。”这句话说明()。
最新回复
(
0
)