首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
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
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
admin
2013-01-15
21
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 rocks 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 lo0k 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.
The author mentions outer space in the first paragraph because ______.
选项
A、the Earth’s climate millions of years ago was similar to conditions in outer space
B、it is similar to the ocean floor in being alien to the human environment
C、rock formations in outer space are similar to those found on the ocean floor
D、techniques used by scientists to explore outer space were similar to those used in ocean exploration
答案
B
解析
第一段最后一句话的意思是:海底一片黑暗,压力比地球表面大上百倍,是人无法进入的区域,在某些方面像空旷的外层空间一样难以进入、遥远。
转载请注明原文地址:https://kaotiyun.com/show/NB2O777K
0
考博英语
相关试题推荐
Colorisveryimportanttomostanimalsforithelpsthemtogetalongintheworld.Color【21】tomakeananimaldifficultforit
"Humanism"hasusedtomeantoomanythingstobeaverysatisfactoryterm.57.Nevertheless,andinthelackofabetterword,
"Dimpy,"asherfriendscallher,heardaboutthehazardsofsmokinginhealthclass."Theyshowedpicturesoflungsofpeoplew
Exactlywherewewillstandinthelongwaragainstdiseasebytheyear2050isimpossibletosay.(111)Butifdevelopmentsin
Tomisorderedtobepresentattheimportantmeeting,______.
Twosubstituteswereusedduringthebasketballgames.
______theclaimaboutGermaneconomicmight,itissomewhatsurprisinghowrelativelysmalltheGermaneconomyactuallyis.
Themanagergaveoneofthesalesgirlsanaccusinglookforher______attitudetowardcustomers.
Studythepictureasfollowing,andwriteanessayofabout250words.Youressaymustbebasedontheinstructionsasfollows:
Tomisorderedtobepresentattheimportantmeeting,______.
随机试题
“安慰剂效应”是指让病人在不知情的情况下服用完全没有药效的假药,却能得到与真药相同甚至更好效果的现象。“安慰剂效应”得到了很多临床研究的支持。对这种现象的一种解释是:人对于未来的期待会改变大脑的生理状态,进而引起全身的生理变化。以下陈述都能支持上述解释,除
下列支出中属于转移性支出的有
肝穿刺的禁忌证是
糖尿病患者,女,45岁。尿糖(}H}),血糖25mmo]/L,使用胰岛素60单位后血糖降到10mmoL/L,此时应注意补充
新生儿硬肿症的发病因素不包括()
按照建设项目竣工环境保护验收管理办法规定的程序,分期建设、分期投入生产或者使用的建设项目,()环境保护验收。
常用于清理铸件的毛边、飞刺、浇铸冒口及铸件中缺陷的切割方法为()。
中等卫校毕业生林某,在乡卫生院工作,2000年取得执业助理医师执业证书。他要参加执业医师资格考试,根据《执业医师法》规定,应取得执业助理医师执业证书后,在医疗机构中工作满()。
下列旋律属于南方民歌的是()
Trustistypicallyinterpretedasasubjectivebeliefinthereliability,honestyandsecurityofanentityonwhichwedepend(
最新回复
(
0
)