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 collapse of the Earth’s magnetic field-which guards the planet and guides many of its creatures-appears to have started abou
The collapse of the Earth’s magnetic field-which guards the planet and guides many of its creatures-appears to have started abou
admin
2012-05-18
50
问题
The collapse of the Earth’s magnetic field-which guards the planet and guides many of its creatures-appears to have started about 150 years ago, the New York Times reported last week.
The field’s strength has decreased by 10 or 15 percent so far and this has increased the debate over whether it signals a reversal of the planet’s lines of magnetic force.
During a reversal,the main field weakens,almost vanishes,and reappears with opposite polarity (极). The transition would take thousands of years. Once completed,compass needles that had pointed north would point south. Areversal could cause problems for both man and animals. Birds,fish,animals that rely on the magnetic field for navigation would find migration confusing. But experts said the effects would not be a big disaster,despite claims of doom and vague evidence of links between past field reversals and species extinctions.
Although a total transition may be hundreds or thousands of years away,the rapid decline in magnetic strength is already affecting satellites. Last month,the European Space Agency approved the world’s largest effort at tracking the field’s shifts. A group of how satellites called Swarm are to monitor the collapsing field with far greater precision. "We want to get some idea of how this would evolve in the near future,just like people trying to predict the weather,"said Gauthier Hulot ,a French geophyslcist working on the satellite plan. "I’m personally quite convinced we shbutd be able to work out the first predictions by the end of the mission."
No matter what the new findings,the public has no reason to panic, Even if a transition is coming on its way, it might take 2,000 years to mature. The last one took place 780,000 years ago,when early humans were learning how to make stone tools. Deep inside the Earth flow hot currents of melted iron. This mechanical energy creates electromagnetism. This process is known as the geophysical generator. In a car’s generator,the same principle turns mechanical energy into electricity.
No one knows precisely why the field periodically reverses. But scientists say the responsibility probably lies with changes in the with changes in the disorderly flows of melted iron,which they see as similar to the gases that make up the clouds of Jupiter.
The author says "...the public has no reason to panic " because __.
选项
A、the transition is still thousands of years from now
B、the transition can be precisely predicted by scientists
C、the process of the transition will take a very long time to finish
D、the new transition will come 780,000 years later
答案
C
解析
本题考查考生推断问题的能力,根据文中内容“No matter what the new findings,the public has noreason to panic,Even if a transition is coming on its way,it might take 2,000 years to mature.”不论新的发现是什么,公众都不必感到恐慌。就算正在发生转变,也要2000年才能实现。我们很容易推断出C符合题意。
转载请注明原文地址:https://kaotiyun.com/show/yWnO777K
0
考博英语
相关试题推荐
Americanshadalwaysbeenpreoccupiedwithreformingtheirsociety,with"makingitover,"andbetweenthe1890sandtheendof
ItisincongruousthatthenumberofBritishinstitutionsofferingMBAcoursesshouldhavegrownby254percentduringaperiodw
Treesthat______theviewoftheoncomingtrafficshouldbecutdown.
获得更多知识的惟一途径是通过教育和培训。知识如同资本、物质资源和汗水一样,已经变成了生产的一个必要因素——也许是最基本的因素。因此,一个社会的教育体系应该是能够向以知识为基础的工作迅速转变,否则这个社会就将不可避免地落在后面。
Nowadays,withplentifuliceandelectricchurning,fewpeoplerecallthesharedexcitementoftheerawhenmakingicecreamwas
Tidesarecreatedmainlybythepullofthemoonontheearth.Themoon’spullcauseswaterintheoceanstobealittledeeper
Tidesarecreatedmainlybythepullofthemoonontheearth.Themoon’spullcauseswaterintheoceanstobealittledeeper
Withallhisexperienceabroadhewasamajorassettothecompany.
Thisplatformwouldcollapseifallofus______onit.
Thepresenceofarmedguards______usfromdoinganythingdisruptive.
随机试题
国务院总理在选举时人选由________提名。()
在下列组织结构中,最有可能产生集权领导的组织形式是()
下列享有对该部长篇小说的著作权的人包括()。音像出版社发行包含影片片头曲的磁带是否侵犯他人著作权?为什么?()
下列不属于动态控制中的三大要素的是()。
根据《合同法》的规定,下列各项中,债权人不可以行使撤销权的情形有()。
依据税法规定,对出口商品退还增值税、消费税的,均不退还已缴纳的城市维护建设税。()
教师公正的核心是()。
随着信息技术的发展,旅游网站成为传播旅游信息资源的重要渠道,是大部分潜在游客出行前搜寻信息的主要参考来源。据统计,有61.2%的旅游者出行时会选择从网上搜寻信息,而且网络旅游信息具有搜寻成本低、传播快的特点,成为重要的信息载体和影响旅游者决策的因素。这段文
空中花园
______hetriedtopassthedrivingtest,hestillfailedthesecondtime.
最新回复
(
0
)