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
Astronomers who study planet formation once believed that comets—because they remain mostly in the distant Oort cloud, where tem
Astronomers who study planet formation once believed that comets—because they remain mostly in the distant Oort cloud, where tem
admin
2020-03-28
87
问题
Astronomers who study planet formation once believed that comets—because they remain mostly in the distant Oort cloud, where temperatures are close to absolute zero—must be pristine relics of the material that formed the outer planets. The conceptual shift away from seeing comets as pristine relics began in the 1970s, when laboratory simulations revealed there was sufficient ultraviolet radiation reaching comets to darken their surfaces and there were sufficient cosmic rays to alter chemical bonds or even molecular structure near the surface. Nevertheless, astronomers still believed that when a comet approached the Sun—where they could study it—the Sun’s intense heat would remove the corrupted surface layer, exposing the interior. About the same time, though, scientists realized comets might contain decaying radioactive isotopes that could have warmed cometary interiors to temperatures that caused the interiors to evolve.
According to the passage, astronomers’ belief that comets are pristine relics was
选项
A、overturned by analysis of what happens when comets approach the Sun
B、supported by what observations revealed about the composition of the outer planets
C、based on consideration of the conditions that prevail where comets are located
答案
C
解析
彗星所在地方的普遍环境条件指的是第一句中的绝对零度的奥尔特星云,prevail对应mostly,因此选项C正确。A项对彗星接近太阳时所发生的事情的分析对应第三句,该句支持了彗星是纯洁的这一观点。B项彗星纯洁与否和外部行星的组成无关。
转载请注明原文地址:https://kaotiyun.com/show/yhVO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
SkilledblacksmithswhocouldforgeusefulitemsoutofironusedtoplayacentralroleinAmericanlife.Theonsetofindustri
Whichofthefollowing,iftrue,bestcompletesthepassagebelow?ThetraditionalviewofHomeristhatofablindbardwho
Howmanyreallysufferasaresultoflabormarketproblems?Thisisoneofthemostcriticalyetcontentioussocialpolicyques
Caffeine,thestimulantincoffee,hasbeencalled"themostwidelyusedpsychoactivesubstanceonEarth."Syn-der,DalyandBr
Twodivergentdefinitionshavedominatedsociologists’discussionsofthenatureofethnicity.Thefirstemphasizestheprimordi
MannisCorporation’sarchivalrecordsarestoredinanobsoleteformatthatisaccessibleonlybyitscurrentcomputersystem;t
4.Politician:Fewerpeopleareenteringthelabormarketnowthanpreviously.Iftheeconomygrows,thedemandformotivateda
Amilepostonthetowpathread"21"onthesidefacingthehikerassheapproacheditand"23"onitsback.Shereasonedthatth
Manyinstitutionsofhighereducationsufferdecliningenrollmentsduringperiodsofeconomicslowdown.Attwo-yearcommunityco
FloatinginthewatersoftheequatorialPacific,anarrayofbuoyscollectsandtransmitsdataonlong-terminteractionsbetwee
随机试题
3岁患儿,曾多次患肺炎,平时无发绀。体检:心前区隆起,心尖冲动弥散,胸骨左缘第2肋间闻及3/6级粗糙的连续性机器样杂音,向颈部传导,有连续性震颤,有水冲脉。该患儿还可有下列哪项体征
初孕妇孕36周,早孕时血压12/8kPa(90/60mmHg),近一周来头痛,眼花伴视物不清1天,突然全身抽搐1次,急诊入院。查神志尚清,血压17.3112.0kPa(130/90mmHg),LOA,胎心148次/分,下述处理哪项正确
()的突出特点是,由于技术的进步及在生产中的广泛应用,使得整个社会生产过程缩短,最终产品生产所消耗的初级产品和中间产品量减少,技术含量的提高使最终产品效用大增,最终制成品取代中间产品占据社会生产的主体地位。
减量化是指在生产、流通和消费过程中减少()
【五院制】
材料1说明了什么?其原因是什么?材料2说明了什么?从理论和实践的结合上说明材料2和3有什么内在联系?
在SQLSELECT查询中,为了使查询结果排序必须使用短语( )。
Areyouworriedbytherisingcrimerate?Ifyouare,thenyouprobablyknowthatyourhouse,possessionsandpersonsareincrea
【B1】【B2】
Theamazingsuccessofhumansasa【1】istheresultoftheevolutionarydevelopmentofourbrainswhichhasled,amongotherthin
最新回复
(
0
)