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
2023-12-27
44
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/3310744.html
相关试题推荐
"Itispainingtowatchpeoplesufferingfromwhatishappeningintheregionof
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
EversincePresidentTrumptappedGinaHaspeltoleadtheCIAnearlytwomonths
AccordingtoUNICEF,around564millionIndians,nearlyhalfthepopulation,
随机试题
[originaltext]TheWorldHealthOrganizationisurgingcountriestofollows
某中国境内上市公司G收购了美国上市公司H,L公司为H公司的控股子公司,其注册地在
桑杏汤治疗咳嗽之何种证型A.风热犯肺 B.风寒袭肺 C.风燥伤肺 D
A.吸潮B.风化C.氧化D.水解E.晶型转变酯类药物容易
地块内如有几个土地利用类别时,以()符号标出分界线,分别标注利用类别。A:地类界
某医院原计划采购普通医用口罩和N95口罩共480箱,采购时因为供货量的问题,将的
近来虽然有降雨,但气温并没有降多少,不少人仍然依赖空调过日子,而干眼症也“趁机上
商业银行过去筹集的资金由于受到内外部因素的影响而发生不规则波动,从而对商业银行的
如果被审计单位某银行账户的银行对账单余额与银行存款日记账由于未达账项的原因导致余
根据《建筑工程建筑面积计算规范》(GB/T50353-2013),不应计算建筑面
最新回复
(
0
)