首页
登录
职称英语
The ocean bottom—a region nearly 2.5 times greater than the total land area
The ocean bottom—a region nearly 2.5 times greater than the total land area
游客
2025-01-23
16
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 be cause 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
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/3926000.html
相关试题推荐
Thedeepertheshadeofyellowoftheolfactoryregion,______thesenseofsmell
Theolfactoryregionsofthenoseareyellow,richlymoist,and______.A、fullyfa
Thelinguistdiscoveredstrikingsimilaritiesbetweenanearly______languagespo
Nearlyallourclothesaremadefromfibersofonesortoranother,iftheyare
"Itispainingtowatchpeoplesufferingfromwhatishappeningintheregionof
Inthemajorpalmoilproducingregions,IndonesiaandMalaysia,itisestimated
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
EversincePresidentTrumptappedGinaHaspeltoleadtheCIAnearlytwomonths
Temperaturerosetothe________limitthroughouttheregionandpeoplewereoblig
随机试题
奥斯本名义上是个医生,但他整天都呆在股票交易所里。Osborneisadoctorinnameonly,buthestaysinthes
"We’renotbringinginmillionsofdollars,"saysadirectorofdevelopment."Bu
Whoisthecaller?[br][originaltext]A:GoldenHotel.MayIhelpyou?B:Mr.J
大型屋架、大跨度桥梁等大负荷预应力混凝土结构中,应优先选用()。A.冷轧带肋钢筋
下列关于资产基础法评估假设的说法中,错误的是( )。A.最佳使用是指市场参与者实
(2017年真题)股权投资基金管理人及其从业人员投资于其所管理股权投资基金的资金
(2020年真题)根据《证券公司为期货公司提供中间介绍业务试行办法》,期货.现货
关于嗜酸性淋巴肉芽肿,正确的是A.又称Kimura综合征 B.好发于青年女性
(2020年真题)下列各项中,关于存货期末计量会计处理表述正确的是()。A.当
矿图中,其坐标网格的间距一般为() A,10cm B,20cm C,30
最新回复
(
0
)