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
2025-01-19
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 fight 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
本题考查代词指代。分析“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.”这句话的结构可知,they在这里指代的是Deep-ocean sediments。所以,答案是C。
转载请注明原文地址:https://tihaiku.com/zcyy/3919678.html
相关试题推荐
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Fornearlyacentury,twoUnitedStatesgovernmentalagencies,theUnitedSt
Fornearlyacentury,twoUnitedStatesgovernmentalagencies,theUnitedSt
Fornearlyacentury,twoUnitedStatesgovernmentalagencies,theUnitedSt
Fornearlyacentury,twoUnitedStatesgovernmentalagencies,theUnitedSt
随机试题
"Youdon’thavetowaitforgovernmenttomove...thereallyfantasticthing
OnthemorningofMay90,1927,CharlesA.Lindberghtookofffromamuddyai
下列有关冬季施工增加费计算的表述中,不正确的是()。A.冬季施工增加费的计
动态网幅(Banner)广告的图像通常是______格式文件。A.BMP B.
甲亢术前准备,脉率应降至每分钟A.110次以下 B.90次以下 C.80次以
贷款分类的目标准备金是否充足提供依据不包括( )。A.揭示贷款的实际价值 B
关于语颤的描述,下列不正确的是A.发音强、音调低、胸壁薄者语颤强 B.左胸上部
教学认识的主体是教师。()
患者女,35岁。右下颌智牙反复肿痛伴开口受限2个月。抗感染治疗有效,但不能根治。
血糖葡萄糖耐量试验
最新回复
(
0
)