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
A、There are different kinds of sound waves. B、Different people have different abilities of sense. C、There are different kinds of
A、There are different kinds of sound waves. B、Different people have different abilities of sense. C、There are different kinds of
admin
2019-09-13
108
问题
Moderator: Good morning, class. Today Professor Liu will give us a lecture about earthquakes. Welcome.
Professor Liu: Thank you. As you know, some earthquakes are not powerful enough to be felt on the earth’s surface while in others, people can, indeed, feel the earth shaking. And of course, there might be violent movement, often with catastrophic results. What we feel during an earthquake or huge explosion are a series of waves called seismic waves.
In an earthquake, you might initially feel some minor trembling, then perhaps violent shaking, and then some more tremors. [16] The reason why you feel these different types of movement is because there are different kinds of seismic waves. There are two major types of seismic waves: body waves and surface waves.
The waves that you feel first are body waves. These mainly travel deep through the earth’s interior rather than at the surface. Some of them travel very fast, and that’s why you feel them first. [17] But because they travel deep inside the earth, they’re felt only as tremors. There are two types of body waves. The first type of body wave is the P wave or primary wave. It’s the fastest kind of seismic wave. These waves can move through any type of material, including rock and fluids. Because of this and because of their speed, these waves are the first to reach the earth’s surface. You likely won’t even hear or feel these waves, but animals may hear them. They’re not strong enough to cause significant damage. The other type of body wave is the S wave or secondary wave. Because S waves travel at half the speed of P waves, you won’t feel them in the beginning.
[18-1] Unlike body waves, surface waves move at or near the earth’s surface. These waves are similar to ripples on water. [18-2] They are usually the most destructive type of seismic wave because of their lower frequency, larger amplitude, and longer duration. There are two types of surface waves. The first kind of surface wave is called a love wave. It’s the fastest surface wave. The other kind of surface wave is the Rayleigh wave. It rolls along the ground just like a wave rolls across a lake or an ocean. As a result, it moves the ground up and down and side to side in the same direction that the wave is moving. [19] Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves. They are slower than body waves, and sometimes cars might appear to be moving up and down with these waves.
Questions 16 to 19 are based on the recording you have just heard.
16.Why do we feel different types of movement in an earthquake?
17.Why do we feel body waves only as tremors?
18.What are the most destructive type of seismic wave?
19.Which seismic wave brings us shaking felt from an earthquake?
选项
A、There are different kinds of sound waves.
B、Different people have different abilities of sense.
C、There are different kinds of seismic waves.
D、The travelling speed of waves differs greatly.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/lHW7777K
0
大学英语六级
相关试题推荐
Googlemustbethemostambitiouscompanyintheworld.Itsstatedgoal,"toorganizetheworld’sinformationandmakeitunive
Theestimatesofthenumbersofhome-schooledchildrenvarywidely.TheU.S.DepartmentofEducationestimatesthereare250,00
Somesayitisevidentthatcomputerscandamageaperson’seyesight.Sincethepopularityofcomputersbegantoskyrocket,ther
Imagineeatingeverythingdeliciousyouwant—withnoneofthefatthatwouldbegreat,wouldn’tit?New"fakefat"products
Naturally,inagroupofanimalsasdiverseasthesnakes,andwithsomanyvariedenemies,therearenumerousdefensivereactio
A、Humansgothelpfromotherspecies.B、Humanssurvivebyexploration.C、Humanssurvivebyingenuity.D、Humanssurvivebyluck.
A、Satisfied.B、Enthusiastic.C、Disappointed.D、Indifferent.C女士谈到,男士一定见证了公司很多的变化,男士回应说绝大部分的变化都是使事情变得更加糟糕。故选C。
A、It’stheultimatecauseofwinds.B、Itcausesverticalmovementsofair.C、Itreducesdifferencesinairpressure.D、It’suse
A、Consumptionandtheimpactontheenvironment.B、Socialstability.C、Economicdevelopment.D、Culturalprosperity.A
A、Abouttwo-thirdsoftheworld’spopulation.B、Abouttwo-fifthsoftheworld’spopulation.C、About80million.D、About8milli
随机试题
角膜接触镜的并发症有
在某温度时,下列体系属于缓冲溶液的是()。
根据《全国主体功能区规划》,优化开发区域的发展方向和开发原则包括()。
对于结构施工、安装装饰装修阶段,防治扬尘污染的规定,下列说法正确的是()。
下列属于设备基础常见质量通病是()。
永续年金是一组在无限期内金额()、方向()、时间间隔()的现金流。
赊销在企业生产经营中所发挥的作用有()。
转让国有土地使用权、地上的建筑及其附着物并取得收入的(),都是土地增值税的纳税义务人。
阅读下面短文,回答问题。利用机会就是乘时;机会稍纵即逝,所以__________而__________以外,还该__________而__________。治生或者说致富的过程,在那时有三个阶段:第一,“无财作力”,以劳力赚钱。稍有积蓄,便是第二
己知一批袋装食品的重量服从正态分布,从中分别抽取样本量为20,50,100的样本,当样本量增大时,样本均值的标准差()。[江苏大学2011研]
最新回复
(
0
)