首页
登录
职称英语
The ocean bottom — a region nearly 2. 5 times greater than the total land ar
The ocean bottom — a region nearly 2. 5 times greater than the total land ar
游客
2025-01-21
7
管理
问题
The ocean bottom — a region nearly 2. 5 times greater than the total land area of the Earth — is a vast
frontier
that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely
inaccessible
, hidden beneath waters averaging over 3, 600 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth’s surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbidding and remote as the void of
outer space
.
Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning of the National Science Foundation’s Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP’s drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean’s surface and drill in very deep waters,
extracting
samples of sediments and rock from the ocean floor.
The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983. During this time, the vessel logged 600, 000 kilometers and took almost 20, 000 core samples of seabed sediments and rocks at 624 drilling sites around the world. The Glomar Challenger’s core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the
strength
of evidence gathered during the Glomar Challenger’s voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth.
The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understanding the world’s past climates. Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years, because
they
are largely isolated from the mechanical erosion and the intense chemical and biological activity that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change — information that may be used to predict future climates. [br] The word "they" underlined in Paragraph 4 refers to________.
选项
A、years
B、climates
C、sediments
D、cores
答案
C
解析
词义题型。根据上下文,此处的they应是物质名词,因而应选C项。
转载请注明原文地址:https://tihaiku.com/zcyy/3922591.html
相关试题推荐
Theheatinsummerisnoless______hereinthismountainregion.A、concentratedB
RainabatesinthefallthroughoutmostoftheAppalachianMountainregion.A、pou
Attemptshavebeenmadefornearlythreedecadestoincreasetheamountofpreci
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
随机试题
______iswrittenbyR.B.Sheridan.A、PamelaB、TheSchoolforScandalC、TomeJones
P公司是一家农产品加工、仓储、物流、销售企业。 2011年,P公司有员工780
红细胞从生成到衰老死亡,平均寿命为A.90dB.110dC.120dD.100d
城市经济学中最常见的城市规模衡量指标有()。A.就业规模 B.空间规模
公积金个人住房贷款实行( )的原则。A.存贷结合、先存后贷、零借整还和贷款担保
下列关于罗马私法的哪一表述是错误的?A、罗马法有市民法和长官法之分,其中长官法的
最可能含有静脉石的是A.血管瘤 B.静脉畸形 C.微静脉畸形
天南有限公司的董事胡某挪用公司大笔资金投资艺术品损失惨重,公司监事因为和胡某私交
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
下列关于项目风险管理的工作流程的说法中,正确的是()。A.项目风险识别的主要任务
最新回复
(
0
)