首页
登录
职称英语
Astronomers who study planet formation once believed that comets—because the
Astronomers who study planet formation once believed that comets—because the
游客
2024-01-10
14
管理
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. [br] 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://tihaiku.com/zcyy/3349653.html
相关试题推荐
BecauseadultiguanasonPlazosIslandaremuchsmallerthanadultiguanasofth
Conservationistshavebelievedthatbyconcentratingtheirpreservationefforts
Cometsdonotgiveofftheirownlightbutreflectlightfromothersources,suc
Theinterviewisanessentialpartofasuccessfulhiringprogrambecause,with
Thegreatestchancefortheexistenceofextraterrestriallifeisonaplanetbe
Becausedinosaurswerereptiles,scientistsonceassumedthat,likeallreptiles
Becauseyoungchildrendonotorganizetheirattentionorperceptionssystematic
MostLargecompaniesprefercustomizedcomputersoftwarebecauseitcanbemolde
Becausetheenemy’snewshipisthequietestanditisthereforethemostelusiv
Sartrebelievedeachindividualisresponsibletochooseonecourseofactionov
随机试题
AGuidetoEatingforSportsThereisapieceofgoodnews
Wecommonlythinkofsportsmanshipinconnectionwithathleticcontests,but
[originaltext]Abitofrainandwindinsummercanbenice.Butbadstorms
在生产力的基本要素中,()占主体地位。 A.劳动者B.生产工具 C.劳动
拟对某批Ⅲ类白色反光膜(无金属镀层)做色度性能试验,请判断。(4)检测仪器有()
根据现行国家统计制度,建筑业总产值包括( )。A.建筑工程产值 B.安装工程
下列具体面临的风险中,属于信用风险的有()。A.家具等家庭财产的损失可能
Thechangeinthatvillagewasmiraculou
拥挤的城市道路具有下列哪种属性?( )A.竞争性与排他性 B.竞争性与非排他
为预防上述材料的类似事件的发生,根据风险与收益相匹配的原则,银行可以选择下列(
最新回复
(
0
)