首页
登录
职称英语
The space between the stars is filled with matter that interstellar conditio
The space between the stars is filled with matter that interstellar conditio
游客
2025-02-19
52
管理
问题
The space between the stars is filled with matter that interstellar conditions should prevent from coalescing into solid particle. Yet surprisingly tiny frozen particles, referred to as interstellar grains, do develop in these spaces. These grains are formed out of chemical elements that are synthesized during thermonuclear fusion in stars and supernova explosions.
The study of interstellar grains has been hampered by the inaccessibility of naturally occurring specimens for use in laboratory experiments. To date, the only source of information about interstellar grains is the stellar electromagnetic radiation that reaches the Earth after passing through regions of space containing interstellar grains. By observing the wavelengths scattered and absorbed by the grains scientists have determined that a grain’s internal structure consists of a core composed of silicates (rocklike material) and a mantle composed entirely of organic compounds. It is hypothesized that each grain begins as a silicate “
seedling
” ejected from a mature star. Continuous physical and chemical evolution then occurs in the mantle formed around the seedling. [br] The author uses the term “seedling” most probably in order to
选项
A、suggest that interstellar grains are much smaller than researchers previously assumed
B、suggest the fragility of the process of interstellar grain formation
C、characterize one kind of interstellar grain
D、suggest that most interstellar grains begin as small particles and grow into larger bodies
E、describe the organic nature of interstellar matter
答案
D
解析
本题属于功能题,定位部分的3s版本便是在介绍星际颗粒的形成过程,因此选项D正确。
转载请注明原文地址:http://tihaiku.com/zcyy/3964278.html
相关试题推荐
Thespacebetweenthestarsisfilledwithmatterthatinterstellarconditio
Thespacebetweenthestarsisfilledwithmatterthatinterstellarconditio
Theconditionofscholarshipdevotedtothehistoryofwomeninphotography
Whenratsareplacedunderconditionsofstress,theiradrenalglandsimmedi
Whatarethedifferencesbetweenwatchinga2Dmovieandwatchinga3Dmovie? W
Whatisthedifferencebetweenthewaychildrenlearnandthewayadultslearn?
Doyouthinkhistorymattersinacountry’sfuturedevelopment? Surely.History
Arethereanydifferencesbetweenyoungpeopleandoldpeopleintermsofdoing
What’sthedifferencebetweenteamsportsandindividualsports? Actually,team
Thetablebelowshowsthefiguresforimprisonmentinfivecountriesbetween
随机试题
HowtoTakeYourTimeHowapersonthinksabouttimecankillhi
现在有不少慈善组织,专门帮助疲惫不堪的旅行者。但是对陌生人友好的老传统在美国仍盛行不衰,尤其是在远离旅游热线的小城镇。“我刚转了一圈,同这个美国人聊了聊
A—presidentB—deanofstudiesC—professorD—lecturerE—AlmaMaterF—alumnusG—st
以下频率中,属于微波波段的是()。A.30Hz B.30KHz C.3
脊柱结核的最好发部位A.胸椎 B.颈椎 C.腰椎 D.尾椎 E.脊柱胸腰
王老师将当地的草编工艺引入课堂,开发了“魅力草编”课程,引导高中生运用各种材料创
因瘀血、砂石、虫、痰等阻塞所致的"气闭"的临床表现是()A.咳嗽频作,呼吸
胡某是甲房地产经纪公司(以下简称甲公司)的房地产经纪人协理,李某是甲公司注册房地
逻辑函数F=f(A,B,C)的真值表如下所示,由此可知( )。
事务文书是物业服务企业表达工作事务所有的书面文书,主要包括以下哪几项内容()。
最新回复
(
0
)