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
For all their great diversity of shapes and sizes, glaciers can be divided into two essential types: valley glaciers, which flow
For all their great diversity of shapes and sizes, glaciers can be divided into two essential types: valley glaciers, which flow
admin
2012-11-30
49
问题
For all their great diversity of shapes and sizes, glaciers can be divided into two essential types: valley glaciers, which flow downhill from mountains and are shaped by the constraints of topography (地貌), and ice sheets, which flow outward in all directions from dome--like centers of accumulated ice to cover vast expanse of terrain. Whatever their type, most glaciers are remnants of great shrouds of ice that covered the earth years ago. In a few of these glaciers the oldest ice is very ancient indeed; the age of parts of the Antarctic sheet may exceed 500,000 years.
Glaciers are born in rocky womb above the snow line, where there is sufficient winter snowfall and summer cold for snow to survive the annual melting. The long gestation period of a glacier begins with the accumulation and gradual transformation of snow flakes. Soon after they reach the ground, complex snowflakes are reduced to compact, roughly spherical ice crystals, and the basic components of a glacier. As new layers of snow and firm, snow that survives the melting of the previous summer, accumulate, they squeeze out most of the air bubbles trapped within and between the crystals below. This process of recrystallization continues throughout the life of the glacier.
The length of time required for the creation of glacier ice depends mainly upon the temperature and the rate of snowfall. In Iceland, where snowfall is heavy and summer temperatures are high enough to produce plenty of melt--water, glacier ice may come into being in a relatively short time--say, ten years. In parts of Antarctica, where snowfall is scant and the ice remains well below its melting temperature year round, the process may require hundreds of years.
The ice does not become a glacier until it moves under its own weight, and it cannot move significantly until it reaches a critical thickness--the point at which the weight of the piled-up layers overcomes the internal strength of the ice and the friction between the ice and the ground. This critica} thickness is about 60 feet. The fastest moving glaciers have been gauged at not much more than two and a half miles per year, and some cover less than 1/100 inch in that same amount of time. But no matter how infinitesimal the flow, movement is what distinguishes a glacier from a mere mass of ice.
Which of the following is NOT true about glaciers?
选项
A、Glaciers are diversified in shapes and sizes.
B、Glaciers can be divided into valley glaciers and ice sheets.
C、Glaciers are remnants of great shrouds of ice that covered the earth years ago.
D、Few glaciers have a long history.
答案
D
解析
根据题干关键词glaciers定位到原文第一段。文中指出:In a few of these glaciers the oldest ice is very ancient indeed;the age of parts of the Antarctic sheet may exceed 500,000 years.可见,有的冰川的冰年龄可能超过50万年,故D项表述有误。
转载请注明原文地址:https://kaotiyun.com/show/scb7777K
0
大学英语六级
相关试题推荐
Infall,thebranchescouldhardly______theweightofthefruit.
Itissometimesdifficulttodiscussmedicalissuesinawaythatisnot______toordinarypeople.
Usethefollowingwordsinsentences,to______theirmeanings.
Itisathatinsuchaprosperouscountrythereshouldbesomanyhomelesspeople.
Studiesshowthatthethingsthatcontributemosttoasenseofhappinesscannotbebought,agoodfamilylifefriendshipandwo
A、Theshoppingmallsarefullofdifferentdesigns.B、Cindyisfondoffashionableclothes.C、Shirtsinbrightcolorareoutof
A、Timealonewilltell.B、Timegoesbyquickly.C、Timewillshowwhatisright.D、Timemakesoneforgetthepast.B短文开头部分中提到Fift
A、ThespeakermakesfunofthePresident.B、Thespeakerthinkshighlyofthefilm.C、ThespeakerisafanofHollywoodcomedies.
Anadvanceddegreeinbusinessstudiesisnowamustforanyambitiousandfocusedexecutivehopingtoclimbthecareerladderi
A、Theyjustlivedinthefirstfloor.B、Theirapartmentbuildingislowerthananormalone.C、Thefloorbelowtheirapartmentw
随机试题
杀灭细菌芽胞最常用最有效的方法是
常用作保护剂的是
黄芩具有的功效是
行动公众指的是不仅意识到组织行为引起的共同问题的存在,而且准备或已经采取某种解决问题的行动的公众。根据上述定义,以下哪项涉及行动公众?
ABC会计师事务所的A注册会计师负责审计甲公司等多家被审计单位2017年度财务报表。与存货审计相关事项如下:(1)在甲公司开始盘点存货前,A注册会计师发现甲公司仓库有大批受托代存存货,甲公司管理层说明了具体情况,审计项目组成员表示理解,并已经将这些情况记
关于政府单位库存物品的会计处理,下列说法中不正确的是()。
Muchoftheworldshouldgoonadietin2014.Morethanathirdofadults【C1】______wereestimatedtobe【C2】______orobesein20
文法G=(VT,VN,P,S)的类型由C中的(32)决定。若GO=({a,b},{S,X,Y},P,S),P中的产生式及其序号如下:1:S→XaaY2:X→Dqb3:Y→XbXla则GO为(33)型文法,对应于(34),由G
Excel工作表D列保存了18位身份证号码信息,为了保护个人隐私,需将身份证信息的第9到12位用“*”表示,以D2单元格为例,最优的操作方法是():
A坐B电影C滑冰D声音E集合F举办例如:她说话的(D)多好听啊!我的爱好很多,比如游泳、()、画画儿和跳舞。
最新回复
(
0
)