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
Glaciers consist of fallen snow that compresses over many years into large, thickened ice masses. Most of the world’s glacial ic
Glaciers consist of fallen snow that compresses over many years into large, thickened ice masses. Most of the world’s glacial ic
admin
2019-02-25
50
问题
Glaciers consist of fallen snow that compresses over many years into large, thickened ice masses. Most of the world’s glacial ice is found in Antarctica and Greenland, but glaciers are found on nearly every continent, even Africa. Presently, 10% of land area is covered with glaciers. Glacial ice often appears blue because ice absorbs all other colors but reflects blue. Almost 90% of an iceberg is below water: only about 10% shows above water. What makes glaciers unique is their ability to move. Due to sheer mass, glaciers flow like very slow rivers. Some glaciers are as small as football fields, whereas others grow to be over 100 kilometers long.
Within the past 750,000 years, scientists know that there have been eight Ice Age cycles, separated by warmer periods called interglacial periods. Currently, the earth is the end of an interglacial, meaning that another Ice Age is due in a few thousand years. This is part of the normal climate variation cycle. Greenhouse warming may delay the onset of another glacial era, but scientists still have many questions to answer about climate change. Although glaciers change very slowly over long periods, they may provide important global climate change signals.
The girth of the ice, combined with gravity’s influence, causes glaciers to flow very slowly. Once a mass of compressed ice reaches a critical thickness of about 18 meters thick, it becomes so heavy that it begins to deform and move. Ice may flow down mountains and valleys, fan across plains, or spread out to sea. Movement along the underside of a glacier is slower than movement at the top due to the friction created as it slides along the ground’s surface.
Most glaciers are found in remote mountainous areas. However, some found near cities or towns present a danger to the people living nearby. On land, lakes formed on top of a glacier, during the melt season may cause floods. At the narrow part of a valley glacier, ice falling from the glacier presents a hazard to hikers below. When ice breaks off over the ocean, an iceberg is formed.
Glaciers are a natural resource and contain 75% of the world’s freshwater. People world-wide are trying to harness the power of these frozen streams. Some towns rely on glacial melting from a nearby ice cap to provide drinking water. Some farmers spread soil or ashes over snow to promote melting, hoping that the melting will provide water to irrigate crops in drought-stricken Areas. Others have channeled melt water from glaciers to their fields. Scientists and engineer shave worked together to tap into-glacial resources, using electricity that has been generated in part by damming glacial melt water.
When a glacier thickens to a critical point, it starts to______.
选项
答案
deform and move
解析
(第三段第二句提到it becomes so heavy that it begins to deform and move。)
转载请注明原文地址:https://kaotiyun.com/show/Xt8K777K
本试题收录于:
B类竞赛(英语专业本科专科)题库大学生英语竞赛(NECCS)分类
0
B类竞赛(英语专业本科专科)
大学生英语竞赛(NECCS)
相关试题推荐
Althoughfewwoulddenythatit’sbettertoberichthanpoor,forsomepeoplethequestformoneyissoall-consumingthatite
Exchangeaglancewithsomeone,thenlookaway.Doyourealizethatyouhavemadeastatement?Holdtheglanceforasecondlong
Everyyearalargenumberofyoungpeopleleaveschoolandbeginwork.Some【D1】______jobsonfarmsorinindustry.Othersacce
Thenumberthatshouldcomenextintheseries64,16,4,1,1/4is______.
WhatwasregardedasthelifebloodofthecountryoftheMaldives?
Ifyoufeeloverwhelmedbyyourcollegeexperiences,youarenotalone—manyoftoday’scollegestudentsare【C1】______(suffer)fro
Hadelectroniccomputersnotbeeninvented,manyproblemsonspaceflight______.
Ithasbeensaidthateveryonelivesbysellingsomething.Inthelightofthisstatement,teacherslivebyselling【C1】kno______
MeltingGlaciersSeveralglaciersintheAlpshavealreadydisappearedinasfewas40year.InthePatagonianicefieldsof
TheHouseofCommonsconsistsof______MembersofParliament.
随机试题
关于非票据结算方式,下列说法正确的有()。
中国各族人民都深深懂得国家分则弱、合则强的道理,反对分裂、反对战乱,希望国家统一、民族团结、人民安居乐业、经济繁荣发展。这体现了中华民族爱国主义传统中【】
某城市道路工程项目,施工承包商考虑到该工程受自然条件的影响较大,为了充分利用有限资金,以最快的速度、最少的消耗确保工程优质,创造最好的经济效益和社会效益,加强了对前期质量控制工作。具体控制工作如下:(1)对道路工程前期水文、地质进行实地调查。调查
在施工图设计阶段,根据施工图纸确定的工程量,套用有关预算定额单价、取费率和利税率等编制()。
由于撤销权的行使具有溯及力,被撤销的合同与无效合同一样,自始没有法律约束力。()
下列各项中,应列入利润表中“营业税金及附加”项目的有()。
社会工作者到一个新的社区,首先通过调查确定想要解决的全面性问题,其次详细列明具体问题及其形成的原因。这一认识和分析问题的方法是()。
项目采购管理是为完成项目工作从承担该项目的组织外部购买或获取项目所需的产品、服务或成果的过程。随着IT行业的快速发展和技术的不断进步,行业的分工更细,更加强调分工与合作。对本企业不能提供,或虽然能提供但不具备竞争力,同时市场已存在的高性价比的产品、服务和成
设x和y均为int型变量,则执行下面的循环后,y值为()。publicclassSun{publicstaticvoidmain(Stringargs[]){intx,y
GuiltyorNotGuiltyManyattemptshavebeenmadeinthepasttoassesstheeffectsofalcoholonroadsafety.Forseveral
最新回复
(
0
)