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
Europa is the smallest of planet Jupiter’s four largest moons and the second moon out from Jupiter. Until 1979, it was just
Europa is the smallest of planet Jupiter’s four largest moons and the second moon out from Jupiter. Until 1979, it was just
admin
2005-01-30
74
问题
Europa is the smallest of planet Jupiter’s four largest moons and the second moon
out from Jupiter. Until 1979, it was just another astronomy textbook statistic. Then
came the close-up images obtained by the exploratory spacecraft Voyager 2, and within
days, Europa was transformed-in our perception, at least-into one of the solar system’s
(5) most intriguing worlds. The biggest initial surprise was the almost total lack of detail,
especially from far away. Even at close range, the only visible features are thin, kinked
brown lines resembling cracks in an eggshell. And this analogy is not far off the mark.
The surface of Europa is almost pure water ice, but a nearly complete absence of
craters indicates that Europa’s surface ice resembles Earth’s Antarctic ice cap. The
(10)eggshell analogy may be quite accurate since the ice could be as little as a few kilometers
thick –a true shell around what is likely a subsurface liquid ocean that , in turn, encases
a rocky core. The interior of Europa has been kept warm over the eons by tidal forces
generated by the varying gravitational tugs of the other big moons as they wheel around
Jupiter. The tides on Europa pull and relax in an endless cycle. The resulting internal heat
(15)keeps what would otherwise be ice melted almost to the surface. The cracklike marks on
Europa’s icy face appear to be fractures where water or slush oozes from below.
Soon after Voyager 2’s encounter with Jupiter in 1979, when the best images of
Europa were obtained, researchers advanced the startling idea that Europa’s subsurface
ocean might harbor life. Life processes could have begun when Jupiter was releasing a
(20)vast store of internal heat. Jupiter’s early heat was produced by the compression of the
material forming the giant planet. Just as the Sun is far less radiant today than the primal
Sun, so the internal heat generated by Jupiter is minor compared to its former intensity.
During this warm phase, some 4.6 billion years ago, Europa’s ocean may have been liquid
right to the surface, making it a crucible for life.
选项
A、The effect of the tides on Europa’s interior
B、Temperature variations on Jupiter’s moons
C、Discoveries leading to a theory about one of Jupiter’s moons
D、Techniques used by Voyager 2 to obtain close-up images.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/5nyO777K
0
托福(TOEFL)
相关试题推荐
Soviet’sNewWorkingWeekHistorianinvestigateshowStalinchangedthecalendartokeeptheSovietpeoplecontinuallyatwork.
Youshouldspendabout20minutesonQuestions27-40,whicharebasedonReadingPassage3below.SourceofKnowledgeAWhatcou
Trytoskimthetextbelowin30secondsanddecidewhichofthefollowingdescribesthemainideaofthetext.AItisimportan
ThePearlA.Thepearlhasalwayshadaspecialstatusintherichandpowerfulallthroughthehistory.Forinstance,women
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
SECTION3Questions21-30Questions21Whichthreeguestsareontheradioprogramme?Writethecorrectletteronyouranswer
Whatpercentageofthestudentsaremature?The______isatSaltLane.
THINGSTODO:geta__________firstfromthesecond-handshop
EngineeringforsustainabledevelopmentTheGreenhouseProject(Himalayanmountainregion)ProblemShortgrowingseason
随机试题
淡菜是由________的肉加工而成的干制品。
突出反映了投资与报酬的关系的指标是()
法治思维是指以法治价值和法治精神为导向,运用法律原则、法律规则、法律方法思考和处理问题的思维模式。法治思维是()
细胞缺氧时最常见的变化是
心动周期中,左心室内压力最高的时间是
某男,8岁。1周前因感受风寒,出现恶寒发热,鼻塞声重,流涕清稀,咽痒,咳嗽。现症见咳嗽气粗,痰多黄稠,烦热口干。舌红,苔黄腻,脉滑数。该患者的治疗原则为()。
编制资产负债表时,“应付职工薪酬”账户期末如为借方余额时,则应以负数在“应付职工薪酬”项目下列示。()
甲公司2×18年度发生如下事项:(1)1月1日,甲公司增发500万股股票取得A公司40%的股权,能够对A公司施加重大影响。当日,甲公司股票的市场价格为每股3.2元,A公司可辨认净资产公允价值的金额为3800万元(与账面价值相等)。当年,A公司实现净利润
老年人享受家庭赡养与扶养的权利除了经济供养、生活照料和精神慰藉等项内容以外,还包括()等特殊需要满足的权利。
苏州弹词“陈派”的创始人是_________。
最新回复
(
0
)