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
From Dr. R. S. Scorer of Britain’s Imperial College of Science comes the latest theory about the cause of lightening flashes. Dr
From Dr. R. S. Scorer of Britain’s Imperial College of Science comes the latest theory about the cause of lightening flashes. Dr
admin
2009-02-10
73
问题
From Dr. R. S. Scorer of Britain’s Imperial College of Science comes the latest theory about the cause of lightening flashes. Dr. Scorer believes the cause is hail falling through super - cooled clouds, lee particles bouncing off the falling hail acquire a positive charge and rise to the top of the cloud while the hail carries a negative charge to the bottom of the cloud.
According to Dr. Scorer, Benjamin Franklin first proved thunderclouds are charged with electricity. Later investigation showed that the tops of the clouds have a great positive charge and the bottoms a great negative charge.
When the charges become great enough to break down the insulating properties of the air, lightening flashes carry the electricity within the cloud, or from cloud to cloud, or from cloud to earth. But the question remained: how do the charges develop within the cloud?
To seek the cause, Dr. Scorer and his colleagues at the college first duplicated thundercloud currents in a liquid tank. They doubt that mixture takes place only in the tops of the clouds.
Next a study of thunderclouds over the North Atlantic showed that lightening occurs only when the air temperature around the cloud is below freezing. Particles at the top of the cloud begin to freeze, but those in the remainder of the cloud stay unfrozen although below freezing temperature.
To measure moisture, the scientists sent planes equipped with external refrigerated rods into the clouds. The idea was that moisture would freeze on the rods and could later be measured. The men found, however, that some of the moisture particles bounced off the rods. This accidental discovery set the scientists on a new course of action.
In the laboratory, S. E. Reynolds whirled a refrigerated rod through ice particles and found that the particles bounced off the rod acquired a positive charge. This was the missing link. Without hail and super-cooled clouds, he concluded there could be no lightening.
What is implied in this passage?
选项
A、Positive charges are in the top of the cloud, negative charges in the bottom.
B、When positive and negative charges within a cloud cannot break down the insulating properties of air, no lightening will be formed.
C、Without hail and thunder, there could be no lightening.
D、Without refrigerated rods, lightening could not be created.
答案
B
解析
见原文第三段“When the charges be-come great enough to break down the insulating proper-ties of the air,lightening flashes carry the electricity... (当电荷足够强大以击穿空气绝缘层时,闪电携带电流……)。”言外之意,当电荷未能击穿空气绝练层时,便不会产生闪电。因此B为正确选项。
转载请注明原文地址:https://kaotiyun.com/show/vH6K777K
0
专业英语四级
相关试题推荐
TheCloningTechnologyI.Thedifferencebetweena【T1】______colonyand【T1】______cloningamammalA.Clarifytheillusion:sc
TheMessagesinDistanceI.Peoplefromdifferentcultures【T1】______differently【T1】______A.NorthAmericansstandabouttwof
AccordingtoOxfordEnglishDictionary,bookis""awrittenorprintedtreatiseorseriesoftreatises,occupyingseveralsheet
Excessivecaloriesfromsugarcancontributetoweightproblems,andsugarisalsowellknownforitsabilitytopromoteteethd
(1)Thesaltequationtaughttodoctorsformorethan200yearsisnothardtounderstand.Thebodyreliesonthisessentialmin
A、Ahighereducation.B、Self-control.C、Considerationofthepresent.D、Self-reliance.B
Atsometimeinyourlifeyoumayhaveastrongdesiretodosomethingstrangeorterrible.However,chancesarethatyoudon
FRANKFURT—IbumpeddowninFrankfurtat10:55AM.AGermanlanding,Ithought—unsubtleandpunctual. Theskywasclear,anu
IfNajibullahZaziiseverythingtheFBIsaysheis,thentheAfghan-bornDenverairport-shuttle-busdriverrepresentsanewk
WherewasthedestinationofTitanic?
随机试题
化妆造型能反映一个人的文化底蕴、审美情趣和修养内涵。()
Internet是一个全球范围内的网络,它通过()将各个网络互联起来。
关于增强子的叙述,不正确的是
诊断根折的依据是()
在20世纪以后建立起来的欧洲司法审查制度中,承担司法审查职责的机关是()
商标注册人需要变更下列注册事项的,可以提出变更申请的有()。
纯公共物品消费的非竞争性特征表现为()。
对一个过分害怕猫的学生,为让他不怕猫,可以先让他看猫的照片、谈论猫、远远观看关在笼中的猫;然后让他靠近笼中的猫;最后让他抚摸猫、抱起猫,消除对猫的惧怕反应。这种治疗方法是()。
我国法律监督类型中作为专门监督的是
若变量已正确定义并赋值,则以下符合C语言语法的表达式是()。
最新回复
(
0
)