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
The Theory of Continental Drift has had a long and turbulent history since it was first proposed by Alfred Wegener in 1910.【F1】V
The Theory of Continental Drift has had a long and turbulent history since it was first proposed by Alfred Wegener in 1910.【F1】V
admin
2017-10-23
43
问题
The Theory of Continental Drift has had a long and turbulent history since it was first proposed by Alfred Wegener in 1910.【F1】
Vigorously challenged yet widely ignored, the theory had languished for half a century, primarily due to its lack of a plausible mechanism to support the proposed drift.
With the discovery of sea-floor spreading in the late 1950’s and early 60’s, the idea was reinvigorated. Plate tectonics is now almost universally accepted. Many details of the mechanism are to be worked out.
The surface of the Earth is divided into approximately six large plates, plus a number of smaller ones. The plates are bounded by an interconnected network of ridges, transform faults, and trenches. Ridges, also called spreading centers, occur where two plates are moving away from each other. As the plates separate, hot molten mantle material flows up to fill the void.【F2】
The increased heat resulting from this flow reduces the density of the plates, causing them to float higher, thus elevating the boundaries by many thousands of feet above the colder surrounding sea floor.
【F3】
Ridges on the ocean floor form the longest continuous ranges of mountains on the planet, but only in a very few places on the Earth do these mountains rise above the ocean surface.
New sea floor is constantly being created along spreading centers. Obviously somewhere else old sea floor must be going away. This occurs in trenches, also called subduction zones. Trenches occur along the boundary between two plates that are moving towards each other.【F4】
Where this occurs, one plate is bent downwards at about a 40°angle and plunges under the other plate’s leading edge, eventually to melt back into the liquid mantle below.
As the subducting plate is heated back up to mantle temperatures, certain minerals in the plate melt sooner than others.【F5】
Minerals that melt at lower temperatures and are lighter than the surrounding material tend to rise, melting their way up through the overriding plate to erupt as volcanoes on the ocean floor.
As these volcanoes grow, they rise above the ocean surface to form lines of islands along the leading edge of the overriding plate. Numerous islands of Micronesia and Melanesia in the western Pacific were created in this way.
【F2】
选项
答案
这种流动所产生的不断增加的热量降低了板块的密度,使板块再向上漂移,将边界提升,从而使其超出周围较冷海底数千英尺的高度。
解析
本句的主干是The increased heat reduces the density…。causing…,thus elevating…作并列伴随状语。本句话的关键是理解其句子结构,找出伴随状语。
转载请注明原文地址:https://kaotiyun.com/show/vcIZ777K
0
考研英语一
相关试题推荐
Intheidealizedversionofhowscienceisdone,factsabouttheworldarewaitingtobeobservedandcollectedbyobjectiveres
CigarettesmokingisahealthhazardofsufficientimportanceintheUnitedStates.Itwas50yearsagothismonththatAmerica’
WhenThomasKeller,oneofAmerica’sforemostchefs,announcedthatonSept.1hewouldabolishthepracticeoftippingatPerS
ManyAmericansregardthejurysystemasaconcreteexpressionofcrucialdemocraticvalues,includingtheprinciplesthatallc
Doyourememberallthoseyearswhenscientistsarguedthatsmokingwouldkillusbutthedoubtersinsistedthatwedidn’tknow
Forthefirsttimeinhistorymorepeopleliveintownsthaninthecountry.InBritainthishashadacuriousresult.Whilepol
Intheearly1960sWiltChamberlainwasoneofonlythreeplayersintheNationalBasketballAssociation(NBA)listedatoverse
In1924America’sNationalResearchCouncilsenttwoengineerstosuperviseaseriesofexperimentsatatelephone-partsfactory
【C1】______.Inthe18thand19thcenturies,industrialization,literacy,andurbanizationbroughtaboutnewtechniquesandforma
随机试题
治疗畏寒肢冷,腰膝酸痛,小便频数,精神疲乏,并见疮疡不敛者。应首选
某男,32岁。双下肢挤压伤,神志尚清楚,表情淡漠,明显口渴,面色苍白,皮肤湿冷,脉搏112次/分,血压90/60mmHg,中心静脉压4cmH2O(0.398kPa),毛细血管充盈迟缓。血pH为7.32。该病人的情况是
正常肺部的叩诊音是( )。
A.湿热泻痢B.血热出血证C.食积气滞,腹胀便秘D.蛔虫病E.疟疾使君子的主治病证是
拱顶储罐与相同容积的锥顶储罐比较,( )。
下列入境人员中拿L字签证的是()。
在WAIS-RC的实施过程中,()是以反应的速度和正确性作为评分的依据。
下面程序运行后,语句”Printi”执行的次数是()。PrivateSubForm_Click()DimiAsInteger,jAsIntegeri=0Doi=i+1Forj=10To1Step-3
YouwillheararadiopresenterinterviewingabusinesswomancalledLindaTaylor.Foreachquestion(23-30),markoneletter
A、Afraid.B、Excited.C、Curious.D、Indifferent.A短文说,最初,人类和其他动物一样很可能也怕火。A正确。Atfirst引导的语义强调之处出题,四个选项都为表示心理活动的形容词,听到什么选什么。
最新回复
(
0
)