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
What is the important discovery about seismic waves mentioned by the instructor?
What is the important discovery about seismic waves mentioned by the instructor?
admin
2016-02-29
24
问题
What is the important discovery about seismic waves mentioned by the instructor?
There were several important discoveries in the early part of last century that helped geologists develop a more accurate picture of the earth’s interior.(15 - 1)The first key discovery had to do with seismic waves. Remember they are the vibrations caused by earthquakes. Well, (15-2)scientists found that they travel thousands of miles through the earth’s interior. This finding enabled geologists to study the inner parts of the earth. You see, the studies revealed that these vibrations were of two types: compression, or P waves, and shear, or S waves.(17)And researchers found that P waves travel through both liquids and solids, while S waves travel only through solid matter. In 1906, a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper. On the other hand, S waves either disappeared or were reflected back. So he concluded that the depth marked the boundary between a solid mantle and a liquid core. Three years later, another boundary was discovered that was between the mantle and the earth’s crust. There is still a lot to be learned about the earth. For instance, geologists know that the core is hot. Evidence of this is the molten lava that flows out of volcanoes. But we are still not sure what the source of the heat is.
选项
A、They occur at regular intervals.
B、They can withstand great heat.
C、They travel through the Earth’s interior.
D、They can record the Earth’s internal temperature.
答案
C
解析
语义理解题。根据句(15—1)、(15—2)可知,最关键的一个发现就是地震波。科学家们发现地震波可以在地球内部传播数千英里。所以C为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/hqWK777K
0
专业英语四级
相关试题推荐
Weinsistthatstudentsshouldgiveatruthfulanswer______withtherealityoftheirworld.
Accordingtothespeaker,thesituationofAmericanfamiliesinthefuturemay
Whatisthepurposeoftheprogramthedeandescribes?
HowdoestheUnitedNegroCollegeFundmakestudents’dreambecometrue?
WhichsolutionisNOTmentionedtosolvethepollution?
Globalwarmingisalreadycuttingsubstantiallyintopotentialcropyieldsinsomecountries—tosuchanextentthatitmaybea
AfteraconcerttourinAsia,CanadaandtheU.S.,hewill______workonafive-languageopera.
Theplane______weflewtoCanadaisverycomfortable.
Inthispassage,thespeakeristryingto______.
He______unwisely,buthewasatleasttryingtodosomethinghelpful.
随机试题
肺泡与肺毛细血管血液之间的气体交换是通过哪种结构实现的()
产程的分期及每个产程初产妇和经产妇所需的时间。
嗜异性凝集试验使用的红细胞是A.O型红细胞B.AB型红细胞C.A型红细胞D.B型红细胞E.绵羊红细胞
某孕妇,25岁,妊娠38周,因血压150/100mmHg收入院。检查:一般情况好,下肢水肿(+),宫底高31cm。估计胎儿体重2600g,胎心率136次/分,尿蛋白(+)。请说出该孕妇的初步诊断为( )。
最易并发颅底骨折的颌骨骨折是()
乳房Paget病是指
下列建设用地取得费用中,属于征地补偿费的有()。
潮湿:干燥
富福利指眼下一些地方政府和企业,为了吸引高端人才,争相开出各种优惠条件,如提供房补、半价专用房等。高端人才往往拥有更高的谋生本领,收人方面已经处于社会的中高端或者高端行列,这一让富有者拥有更多福利的政策偏向引发人们质疑。有人认为此举是将大量的公共资源向高端
A、Protectingroadsalongtheshore.B、Buildingonbeacheswithseawalls.C、Addingsandtobeacheswithseawalls.D、Stoppingbuil
最新回复
(
0
)