首页
登录
职称英语
Comets are now known to contain twice as many atoms of deuterium to
Comets are now known to contain twice as many atoms of deuterium to
游客
2025-02-22
9
管理
问题
Comets are now known to contain twice as many atoms of deuterium to
each atom of ordinary hydrogen found in seawater. Scientists have also
discovered that meteorites could not solely have delivered the water in the
Line ocean, for then the earth’s atmosphere would contain nearly 10 times as much
(5) xenon as it actually does, given that meteorites carry excess xenon. Hence, the
best model for the source of the oceans at the moment is a combination of water
derived from comets and water caught up in the rocky body of the earth as it
formed. This mixture satisfies both the xenon and deuterium problem, the
latter especially if the rocky material out near the earth’s present orbit
(10) collected some regularly composed local water from the solar nebula before they
accreted to form the earth. New laboratory studies have indicated that the
water vapor in the solar nebula would have had a low enough proportion of
deuterium to complement the excess deuterium found in comets. [br] According to the passage, scientists have concluded which of the following from the discovery of the large amount of deuterium found in comets?
选项
A、Comets do not contain enough deuterium to have solely created the Earth’s oceans.
B、Given the ratio of deuterium to ordinary hydrogen in seawater, comets cannot have contributed to the Earth’s oceans.
C、It is likely that comets contain less Xenon than meteorites do.
D、Given the low level of deuterium in the waters of Earth’s oceans, comets cannot be its sole source.
E、Comets now play a greater role in the creation of the Earth’s oceans than was previously thought.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3967503.html
相关试题推荐
Cometsarenowknowntocontaintwiceasmanyatomsofdeuteriumto
Cometsarenowknowntocontaintwiceasmanyatomsofdeuteriumto
Skincontainsmillionsofsensoryreceptorswhichinformthebrain,throughelec
Althoughitdoescontainsomepioneeringideas,onewouldhardlycharacterizeth
Theconclusionofsuchavastandcomplexbookshouldhavecontaineda(i)______
Themagazinearticlediscussingthegovernor’sfinancialdealingscontained(i)_
InJapaneseaesthetics,especiallybutnotonlyinNoh,beautycontainstheidea
Theskinofthepoisondartfrogcontainsdeadlypoisonscalledbatrachotoxins.
TheNationalArchivescontaininformationso______thatresearchershavebeenk
Astronomerswhostudyplanetformationoncebelievedthatcomets—becausethe
随机试题
1 Television—themostpervasiveandpersuasiveofmoderntechnologies,markedb
ThethemeofThanksgivinghasalwaysbeen______.A、friendshipandhappinessB、pe
Inafranticsocietywhereefficiencyisputgreatemphasison,maybeitish
Equipmentnot______officialsafetystandardshasallbeenremovedfromthework
各种核算组织程序下采用的总分类账均为借、贷、余三栏式。()
无民事行为能力人、限制民事行为能力人的监护人是其法定代理人。( )
机体的抗肿瘤免疫效应机制中起主导作用的是A、体液免疫 B、细胞免疫 C、巨噬
下列关于股票内部收益率的描述,正确的有( )。 Ⅰ在同等风险水平下,如果内
假设证券市场禁止卖空交易,如果证券市场上存在着如下所述的三个证券组合A、B和C,
患者,男,63岁。晨起床时,发现言语不清,右侧肢体不能活动。既往无类似病史。发病
最新回复
(
0
)