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
9
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] Deep-ocean sediments provide better information about the world’s past climate because they________.
选项
A、are well protected
B、have land-based evidence
C、are in isolation
D、have a longer history
答案
A
解析
细节题型。答案出自第四段第二句Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years...
转载请注明原文地址:https://tihaiku.com/zcyy/3922592.html
相关试题推荐
Theheatinsummerisnoless______hereinthismountainregion.A、concentratedB
Itisknowntoallthatchildreninthisregionhavestrong______toswimmingin
RainabatesinthefallthroughoutmostoftheAppalachianMountainregion.A、pou
Attemptshavebeenmadefornearlythreedecadestoincreasetheamountofpreci
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandar
随机试题
ThecriminalthepolicehadcaughtwasanEnglishman.[br]PaulandNoradecided
【S1】[br]【S10】F)。空格位于名词activities之前,需要填入形容词。该句意为:那些生活习惯健康的人……最不会因为工作而错过个人或家庭活动,
肾血管性高血压发病特点,以下哪项是错误的()A.青年常小于30岁,女性居多;
一艘游轮从甲港口顺水航行至乙港口需7小时,从乙港口逆水航行至甲港口需9小时。问如
A. B. C. D.
社会工作者在策划方案时应掌握的基本要求有()。A.目标清晰而且现实 B.
福利管理的一个重要方面是如何对现存的福利项目和措施进行管理,包括( )。A.处
烟草中主要的致癌物质是A.醛酸类 B.重金属 C.吲哚吡啶 D.尼古丁
熔断器的选择和校验条件不包括( )。A.额定电压 B.动稳定 C.
下列工程管理信息资源中,属于工程组织类信息资源的是()。A.质量控制信息 B
最新回复
(
0
)