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
Because of its precision, the Cepheid-variable method of correlating the luminosity of Cepheid stars with those of known
Because of its precision, the Cepheid-variable method of correlating the luminosity of Cepheid stars with those of known
admin
2011-01-17
97
问题
Because of its precision, the Cepheid-variable method of correlating the
luminosity of Cepheid stars with those of known types of ordinary stars is one of
the most important tools that astronomers have for ascertaining distances to
Line proximate galaxies. Fortunately, Cepheids are luminous enough to be observed
(5) in other galaxies, not just in our own, such that scientists have established a
benchmark for their true brightness. One first observes a Cepheid, notes the
time span for its luminance to vary, and plots that information on an already
established graph to derive its intrinsic luminosity. Comparing intrinsic
luminosity with apparent brightness allows one to calculate the star’s distance
(10) as long as the period-luminosity relation for the star in question is first corrected
for gravitational interference, parallax, and experimental error. Data gathered
by this process would suggest that the universe is expanding, but the method is
less reliable in the nether reaches of the universe, where the crucial evidence
for cosmic expansion would likely be spotted.
The passage is primarily concerned with
选项
A、describing an important technique
B、discussing a new method
C、investigating a controversial procedure
D、announcing a significant discovery
E、promoting a novel application
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/B9jO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Shereferstomeasherclosestanddearestfriend,______wemetjusttwoweeksago.
WhetheryouarehikingthroughthemagnificentredwoodsofNorthernCalifornia,sleepingunderthebrilliantstarsoftheTexas
Hegotinjuredbecauseofhisfaultybrakes.He______toseeifhisbrakeswereworkingproperly.
Ifyouare______aboutotherteachingmethods,we’lldiscussthemlater.
Haveyoueverheardofapawpaw(木瓜)?Ifnot,donotfeelbad.ManyAmericansdonotknowofthefruit,althoughitisnativeto
AtfirstIthoughtthatmathproblemwouldberatherdifficult,butit______tobefairlyeasy.
SupernovasintheMilkyWayarethelikeliestsourceformostofthecosmicraysreachingEarth.However,calculationsshowthat
Forthousandsofyears,nomads,conquerors,traders,andpilgrimshave(i)______theregion,contributingtoitsmulticulturalhe
随机试题
试述政策系统与政策行为者的关系。
《掷铁饼者》的作者是希腊雕塑家【】
在孕早期,对月经不规律的孕妇推算其孕周,以下哪种方法最可靠
患者接受顺铂化疗时,药师应重点监测的不良反应是()
已知反应N2(g)+3H2(g)→2NH3(g)的△rHm<0,△rSm<0,则该反应为()。
军用卫星中应用最广的是()。
根据以下资料,回答问题。能够正确描述2015年新能源汽车产业五种专利申请数占比的统计图是()。
废藩置县
请结合具体作品论述纪录片的美学特征与文化价值。
下列关于光纤分布式数据接口FDDI的描述中,不正确的是()。
最新回复
(
0
)