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
2023-12-31
23
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 stretchingback hundreds of millions of years,because they are largely isolated from the mechanical ero—sion and the intense chemical and biological activity that rapidly destroy much land-based evi-dence 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/3322044.html
相关试题推荐
Mydressdoesn’tfitmearoundtheneck______right.A、quiteB、barelyC、nearlyD、r
Greatereffortstoincreaseagriculturalproductionmust______iffoodshortagei
Thestormhascaused______tothisregion.A、manydamagesB、muchdamagesC、muchda
Inmountainousregions,muchofthesnowthatfallsiscompactedintoice.A、brok
Theolfactoryregionsofthenoseareyellow,richlymoist,and______.A、fullyfa
Insuranceisthesharingof【C1】______.Nearlyeveryoneisexposed【C2】______r
Insuranceisthesharingof【C1】______.Nearlyeveryoneisexposed【C2】______r
Insuranceisthesharingof【C1】______.Nearlyeveryoneisexposed【C2】______r
Insuranceisthesharingof【C1】______.Nearlyeveryoneisexposed【C2】______r
Insuranceisthesharingof【C1】______.Nearlyeveryoneisexposed【C2】______r
随机试题
Executivecoachingisprimarilyconcernedwithconfidentialone-to-onediscu
GaspricewarningascoldMarchleadstoshortsuppliesA)Thecolds
Haiti’sTourismA)LikemanyofitsCaribbeanneighb
Canyouimaginehowyouwouldfeelifyoufelldangerouslyillandcouldnot
[originaltext]M:Janetisquiteinterestedincamping,isn’tshe?W:Yes,sheo
定期进行护理安全隐患报告,属于风险管理的A.风险鉴别 B.风险评估 C.风险
在绝大多数人中A、胆囊管汇合于右肝管 B、胆囊管汇合于肝总管 C、胆囊管汇合
男性,57岁,进食后梗噎感半年,近一个月只能吃软食,伴胸骨后疼痛,饮酒近40年,
心导管检查右心室血氧含量高于右心房的先心病是( )。A.房间隔缺损 B.室间
关于施工总承包管理方主要特征的说法,正确的是()。A.在平等条件下可通过竞标获
最新回复
(
0
)