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
25
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
MaryandJohnarebusylookingforahotelfortheirwedding_____.(2012-67)A、mea
Today,mostcountriesintheworldhavecanals.Somecanals,suchastheSue
初中化学《化合价》 一、考题回顾 二、考题解析 【教学过程】
“三湾改编”的主要内容及意义是什么?
电梯工程隐检主要包括()。A.电梯质量验收报告B.电梯钢丝绳头灌注C.电梯
男性,40岁。低热、腹胀6个月,伴乏力、盗汗、体重减低、乳房发育,查体:全腹膨隆
患者,男,60岁。有慢性支气管炎及肺心病病史。近1周感冒后出现咳嗽,咳黄痰,心悸
川乌断面的多角形环纹是A.外皮层B.内皮层C.形成层D.石细胞环带E.纤维层
期货公司应当任用通过从业资格考试的人员担任高级管理人员。( )
下列犯罪嫌疑人、被告人中,哪些不适用取保候审? A.甲在取保候审期间故意实施
最新回复
(
0
)