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
考研
Despite the fact that comets are probably the most numerous astronomical bodies in the solar system aside from small meteor frag
Despite the fact that comets are probably the most numerous astronomical bodies in the solar system aside from small meteor frag
admin
2011-03-11
32
问题
Despite the fact that comets are probably the most numerous astronomical bodies in the solar system aside from small meteor fragments and the asteroids, they are largely a mystery. Scientists do not know exactly what comets are or where they come from. Educated guesses are the best we have in hand.
Considering the role of comets in legend and the memory of man, it is remarkable that we still know so little, relatively, about them. The most famous comet of all, Halley’s Comet ( named for the man who predicted its return), was first sighted by the Chinese in 240 B.C., and it has returned to terrify the people of the world on a regular basis every since then. The ancient considered it an object of ill omen. By mysterious coincidence, the arrival of Halley’s Comet coincided with such events as the battle of Hastings in 1066, the Jewish revolt of 66 A.D., and the last battle of Attila the Hun against the Romans. Nor is it the only comet to fill man with awe, but merely the most famous in a rich aristocracy of blood-freezers.
Comets are even more fascinating to amateur astronomers than to professionals, because this is one area where amateurs can make major discoveries. Comet Ikeya Seki, one of the brightest comets to appear in this century was discovered in 1965 by a pair of Japanese amateurs, Ikeya and Seki. The person who discovers a new comet gets his (or her) name put on it. And amateurs have a head start in the race to discover new comets; the shorter focal lengths on their smaller telescopes give them a positive advantage over the huge telescopes such as Mount Wilson which is built to scan for galaxies, not comparatively short distances.
Most scientists tend to agree with astronomer Fred T. Whipple that a comet is really a large mushy snowball of frozen ices and gases ( ammonia, methane, possibly carbon dioxide) with a few bits of solid particles stuck inside. But no one is sure how comets are created in the first place.
Scientist believe that comets don’t exhibit their characteristic tail while they lurk fat out in space away from the warmth of the sun but, rather, wander in the form of frozen lumps, like icebergs. This is the core of the comets. Only when the comet approaches the heat of the sun, does the ice begin to melt and stream away in the form of visible gases. The tails of the comets stream out behind for, literally, astronomical distances. Halley Comet had a tail of 94 million miles long when it visited here in 1910.The Great Comet of 1843 had a tail of 186 million miles long.
At the beginning of the text, the author indicates that______.
选项
A、comets are the most commonly seen astronomical bodies
B、comets, meteor fragments and the asteroids are mysterious
C、not much is known about comets
D、nothing do we know about comets except guesses
答案
C
解析
文章句首提到了“尽管彗星在太阳系很可能是除了流星小碎片和小行星以外数量最多的天体,但是它们对人们来说基本还是个谜。”仅由此信息不能得出“彗星是最常见的天体”这一结论,故排除A;该句说“它们是个谜”。从语义和语法角度讲,都只可能指代的是“comets”,故B错误;结合对B项的分析和首段第二句,可以得知C为正确选项。
转载请注明原文地址:https://kaotiyun.com/show/z2p4777K
0
考研英语一
相关试题推荐
Humanshavealteredtheworld’sclimateby(1)_____heat-trappinggasessincealmostthebeginningofcivilizationandevenprev
There(1)_____notonetypeofreadingbutseveralaccordingtoyourreasonsforreading.Toreadefficiently,youhaveto(2)__
Astothepunishmentthatchildrenundersevenareassignedtowrongdoing,PiagetsuggestsItcanbeinferredthattheterm"pu
Astothepunishmentthatchildrenundersevenareassignedtowrongdoing,PiagetsuggestsKeasey’sfindingssupporttheconclu
Writeacompositiononthetopic:TheRighttoDieontheoutline(giveninChinese)below:医学的技术进步可以使人们能比过去活得长。然而,一些人们,包括一些
Whatisoneofthefundamentalprinciplesofdirectcarving?ThepiecetitledThePriestesshasallofthefollowingcharacteri
Thefirsttwostagesinthedevelopmentofcivilizedmanwereprobablytheinventionofprimitiveweaponsandthediscoveryoff
AccordingtothosewhosupporttheliberalizationofEurope’senergymarkets,energysupplymonopolyisunlikelyonthegrounds
Manyteachersbelievethattheresponsibilitiesforlearningliewiththestudent.(1)_____alongreadingassignmentisgiven,
随机试题
某企业批量生产一种零件,投产批量为6件,经过4道工序加工,按照加工顺序,单件每道工序作业时间依次为10分钟、8分钟、20分钟、15分钟,假设零件移动用时为0,为保证生产过程中的连续性和节奏性,该企业对该种零件生产过程进行时间组织,并对工序时间的移动方式进行
2020年4月,在深圳证券交易所主板上市的甲公司与乙有限责任公司(以下简称“乙公司”)达成合并意向。甲公司董事会拟订的合并及配套融资方案(以下简称“方案初稿”)包括以下要点:(1)甲公司吸收合并乙公司,合并完成后,甲公司存续、承接乙公司全部资产和负债,乙
A、有特殊香气,味微甜B、气香特异,味微苦C、气微,味微苦而涩D、气微,味微甜而后苦涩E、气微,味微苦而酸板蓝根的气味为
建筑按功能要求可以选用钢筋混凝土结构的,因工程地质原因造成的地基承载力、承载变形及其不均匀性的问题,要采用()。
商品流通企业的管理信息系统是一个人机系统,体现在()。
恋物癖、同性恋是()。
对于美国人口总体来说平均的期望寿命是73.9岁,但是在夏威夷出生的小孩子将平均活到77岁,而那些在路易斯安那出生的人将平均活到71.7岁。如果一对从路易斯安那来的新婚夫妇在夏威夷开始他们的家庭生活,那么,他们的孩子预期将比他们留在路易斯安那的情况下活得更长
琵琶曲《十面埋伏》描述的是()的情景。
A、Theeditorinchiefdidn’tknowthatthefigureswereaccurate.B、Theeditorinchiefexpresseddoubtabouttheaccuracyofth
WehavetendedtoviewYoga(瑜珈)asakindofforeignreligiousexercise.Butinfactfromamedicalstandpoint,theage-oldseto
最新回复
(
0
)