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、They travel deep inside the earth. B、They travel slow inside the earth. C、They are too small to be felt. D、They travel too fas
A、They travel deep inside the earth. B、They travel slow inside the earth. C、They are too small to be felt. D、They travel too fas
admin
2019-03-17
85
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、They travel deep inside the earth.
B、They travel slow inside the earth.
C、They are too small to be felt.
D、They travel too fast to be felt.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/sdH7777K
0
大学英语六级
相关试题推荐
《史记》(RecordsoftheGrandHistorian)是中国第一本纪传体通史(generalhistorybasedonbiography),由中国西汉时期的历史学家司马迁编写。该书由五部分组成,共130篇,五十多万字,记载了古代
计划生育(familyplanning)是中国的一项基本国策。20世纪70年代末,为了控制人口过度增长,中国政府开始推行计划生育,提倡一对夫妇只生一个孩子。这项政策有效缓解了人口对资源、环境的压力。21世纪初,中国政府对计划生育政策做出了一些调整,允许双
Wemightbelivingforlongerthanever,butwearesick.About95percentofpeoplehaveatleastonehealthcomplaint,witha
A、Menwithsleepapneaseldomshowedbrainproblems.B、Womenwithsleepapneaweremorelikelytobecomedepressed.C、Mostcases
A、Anarticleaboutthelatestnews.B、Aresumeandsomephotographworks.C、Anessayforaliteratureclass.D、Aself-introducti
A、Theywerethemostterribledisasteronearth.B、Theywerewarningsignsofsomebigevents.C、Theywereturnoversofthebig
Ourbodiesexperienceanebbandflowofenergythroughouttheday.Thisiscalledacircadianrhythm,andithasbeenstudied【C
Inmanystressfulsituationsthebody’sresponsescanimproveourperformance.Webecomemore【B1】______,morealert,betterabl
A、Reachingonlynineteenpercentoftheworld’spopulation.B、Neglectingagreatmajorityoftheworld’slanguages.C、Havingtoo
Lastyearatairportsacrosstheworld,18%offlightsweredelayed,leavingmillionsofpassengersstuckwithalotoftimeon
随机试题
减少了焊缝工作截面和接头________主要原因是焊接中气孔的存在。
当呼吸幅度减小而呼吸频率加快时,受影响最大的是
患者女性,67岁,发现乳腺包块1个月余,伴乳头溢液,X线图像如下,最有可能的诊断是
同一原子中,下列壳层电子离原子核最近的是
讲述活动是以培养学前儿童独立构思和表述一定内容的语言能力为基本目的,给儿童提供积极参与命题性质的实践机会。从讲述对象的特点分,可分为()。
“君当作磐石,妾当作蒲苇,蒲苇韧如丝,磐石无转移。”这一句子出自()。
3,7,2,47,(),2252
乙自认为甲需要一栋别墅,于是伪称自己是甲的代理人,以甲的名义与不知情的丙开发商签订买卖合同约定:丙开发商将一栋别墅以500万元的价格卖与甲。关于买卖合同,下列说法正确的有()。
请在【答题】菜单下选择【进入考生文件夹】命令,并按照题目要求完成下面的操作。注意:以下的文件必须都保存在考生文件夹下。中国的人口发展形势非常严峻,为此国家统计局每10年进行一次全国人口普查,以掌握全国人口的增长速度及规模。按照下列要求完
Yahoo!UserResearchYahoo!NeedsYou!HelpusshapethefutureofYahoo!byjoiningo
最新回复
(
0
)