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
2019-09-13
69
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/qHW7777K
0
大学英语六级
相关试题推荐
Theideaofusingyourdishwashertocookamealhasbeenaroundsincethe80s.It’sbeenusedtocook【C1】______mainlyfish.Th
Somemarriagesseemtocollapsesosuddenlythatyou’dneedacrystalballtopredicttheirdemise(灭亡).Inothercases,though,
Whilethemissionofpublicschoolshasexpandedbeyondeducationtoincludesocialsupportandextra-curricularactivities,the
Googlemustbethemostambitiouscompanyintheworld.Itsstatedgoal,"toorganizetheworld’sinformationandmakeitunive
Inthe1920sAmericaenjoyedwhatwastobecomeknownas"anAgeofExcess".From1921-1929manufacturingoutputincreasedwith
Imagineeatingeverythingdeliciousyouwant—withnoneofthefatthatwouldbegreat,wouldn’tit?New"fakefat"products
Itisnogooddwellingonthepast.Whatexistedorhappenedinthepastmayhavebeenbeautifulorexcitingandmaynowbringp
Manycountrieshaveaholidaytocelebrateworkers’rightsonoraroundMay1,butLabourDayinCanadaiscelebratedonthefir
A、Thosehavingatasteorsmellcomponent.B、Productspotentiallyembarrassingtobuy.C、Thosethatrequireverycarefulhandlin
A、Aninterpreter.B、Aforeignlanguageteacher.C、Atourguide.D、Ajournalist.C
随机试题
A、Hediedsevenyearsago.B、Hewasinjuredintheattack.C、Hewasagainstterrorism.D、Hewasonceputintoprison.D新闻中提到,Afi
两个或两个以上实验室之间的比对是在一定时间范围内,按照_________,测量同一个性能稳定的传递标准器,通过分析测量结果的量值,确定量值的一致程度。
一项研究发现,1970年调查的孩子中有70%曾经有过牙洞,而在1985年的调查中,仅有50%的孩子曾经有过牙洞。研究者们得出结论,在1970一1985年这段时间内,孩子们中的牙病比率降低了。下列哪项如果为真,最能削弱上面研究者们得出的结论?
下列哪种类型的休克首选糖皮质激素治疗
(武汉大学考研真题)简述股份有限公司股份转让及法律对特定人员转让股份有限公司股份的限制。
Afteralonganddifficultstrike,theplantworkerswillshowuptowork______Monday.
《文化和旅游部关于实施旅游服务质量提升计划的指导意见》指出,实施导游和领队专业素养研培计划,不断提升导游和领队(),增强主动传承和弘扬社会主义核心价值观的意识。
下列关于行纪合同与居间合同的说法,正确的是()
Howmanypeoplewerekilledinthebombingaltogether?
Inwhatwayishistoryimportanttous?Theword"incompatible"inthelastparagraphmostprobablymeans"______".
最新回复
(
0
)