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
40
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 author refers to the ocean bottom as a "frontier" in Paragraph 1 because it______.
选项
A、is not a popular area for scientific research
B、contains a wide variety of life forms
C、attracts courageous explorers
D、is an unknown territory
答案
D
解析
推断题型。 参看第一段第二行…vast frontier that even today is largely unexplored and uncharted.
转载请注明原文地址:https://tihaiku.com/zcyy/3310737.html
相关试题推荐
我们呼吁发达国家加快技术转让、扩大市场准入、减少贸易壁垒。Wecallforgreatercommitmentandactionsonthep
ArecentstudybyOxfordUniversityestimatesthatnearlyhalfofalljobsin
这种“自下而上”式的改革方式,力求进一步理顺中央和地方的金融管辖权,有效缓解中小企业融资难。This"bottomtotop"approachtof
ArecentstudybyOxfordUniversityestimatesthatnearlyhalfofalljobsi
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
Theoceanbottom—aregionnearly2.5timesgreaterthanthetotallandarea
随机试题
Booking.comB.V.,partofthePricelineGroup,ownsandoperatesBooking.
Everythinghasitsgoodandbadpoints.Fame,too,hasitsadvantagesanddis
Ourschoolsinginggroupisgoingtogive______performancenextmonth;don’tm
DoctorGreenwentonwithhisexperimentonhumanbeing______thedebategoingo
Washington’sNationalParkFundwasfoundedin1993byagroupofenthusiast
刘某,男,45岁,身高175cm,体重95Kg。从事行政管理20年,睡眠不足,餐
某些食品包装袋内有一小包物质用,来吸收氧气和水分,以防止食品腐败,常称“双吸剂”
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
男性,48岁,近1周内发现血压升高156/98mmHg,服用利尿剂氢氯噻嗪降压效
肌糖原不能分解为葡萄糖直接补充血糖是因为肌肉中无 A.糖原磷酸化酶B.脱支酶
最新回复
(
0
)