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 Canadian researcher has discovered that sound travels 【21】______ air more than one-haft kilometer an hour slower than had been
A Canadian researcher has discovered that sound travels 【21】______ air more than one-haft kilometer an hour slower than had been
admin
2010-06-30
43
问题
A Canadian researcher has discovered that sound travels 【21】______ air more than one-haft kilometer an hour slower than had been believed. The discovery has surprised many engineers and scientists who learned they had been 【22】______ the wrong speed of sound for many years.
The speed of sound in air had been 【23】______ to be three-hundred-thirty-one-point-two-nine meters a second. But Doctor George Wong found, 【24】______ accident, that the speed of sound is only three-hundred-thirty-one-point-one-three meters a second. That is a difference of about sixteen centimeters a second.
Doctor Wong is a member of the National Research Council of Canada. He was studying ways to 【25】______ exactly the sound created by microphones. One of his experiments 【26】______ a number he could use to find the speed of sound. He was 【27】______ to learn that the speed of sound was slower than scientists had thought.
To explain the difference, Doctor Wong spent eighteen months 【28】______ past test research on the speed of sound. He finally found the 【29】______ of the difference. It was a mathematics mistake 【30】______ in Nineteen-Forty-Two by physicist H-C Hardy.
Doctor Wong’s 【31】______ does not mean a big change for the science of sound. This is 【32】______ Doctor Hardy and Doctor Wong measured the speed of sound for what is called " standard air".
Standard air exists only 【33】______ thought. It is a way for scientists to agree 【34】______ the same speed of sound. 【35】______ the air around us, standard air always has a temperature of zero degrees Celsius and the same atmospheric pressure 【36】______ the air at sea level. Standard air al ways have same amounts of nitrogen, oxygen, carbon dioxide and 【37】______ gases. And in standard air, the speed of sound does not change.
The change in the new speed of sound is 【38】______ small to affect the work of most sound scientists and engineers. But scientists say Doctor Wong’s discovery may 【39】______ improve instruments 【40】______ use the speed of sound to measure very short distances.
【28】
选项
A、learnt
B、learn
C、studied
D、studying
答案
D
解析
learn和study都有“学习、学会”的意思。但是,study还有对某个课题进行深入的研究之意。spend sometimes doing something指花(时间)做(事情),因此 D为正确选项。这句话的意思是“为了解释其区别所在,Wong博士花了18个月研究过去对声速的测试”。
转载请注明原文地址:https://kaotiyun.com/show/oxJd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Payandproductivity,itisgenerallyassumed,shouldberelated.Buttherelationshipseemstoweaken【C1】______peoplegetolder
Payandproductivity,itisgenerallyassumed,shouldberelated.Buttherelationshipseemstoweaken【C1】______peoplegetolder
Fordecades,postersdepictingrabbitswithinflamed,reddenedeyessymbolizedcampaignsagainstthetestingofcosmeticsonani
Fordecades,postersdepictingrabbitswithinflamed,reddenedeyessymbolizedcampaignsagainstthetestingofcosmeticsonani
Fordecades,postersdepictingrabbitswithinflamed,reddenedeyessymbolizedcampaignsagainstthetestingofcosmeticsonani
Fordecades,postersdepictingrabbitswithinflamed,reddenedeyessymbolizedcampaignsagainstthetestingofcosmeticsonani
FewwritersareasreveredasJaneAusten.AccordingtoapollinMarch,PrideandPrejudice—aromancewithoutasinglekiss—is
A=RotherhitheB=BarnesC=WillesdenD=King’sCrossWhichcity...usedtohavelotofproblemssuchasdrugs,streetc
Periodicallyinhistory,therecomeperiodsofgreattransitioninwhichworkchangesitsmeaning.Therewasatime,perhaps10,
A=RotherhitheB=BarnesC=WillesdenD=King’sCrossWhichcity...usedtohavelotofproblemssuchasdrugs,streetcri
随机试题
GreenTransportationGreentransportationchoicesprovideyouwiththekeystothekingdomasyoutravel.Youcanwalkofft
A.风痰闭阻证B.痰火扰神证C.瘀阻脑络证D.心脾两虚证E.心肾亏虚证病机为“痰浊蕴结,气郁化火,痰火内盛,上扰脑神”的痫病可辨证为
A.泽泻B.绿豆C.冬虫夏草D.大蒜瓣E.荜澄茄与牡丹皮同贮的是()。
准贷记卡透支()。
20世纪后期,陕西凤雏村出土了刻有“凤”字的甲骨四片,这些“凤”字的形体大致相同,均为头上带有象征神权或王权的抽象化了的毛角的短尾鸟。东汉许慎《说文解字》云:“鸑鷟,凤属,神鸟也。……江中有鸑鷟,似凫而大,赤目。”据此,古代传说中鸣于岐山、兆示周王朝兴起的
居住在某市南区的唐某向本市电信局支付2000元初装费安装电话一部,2个月后,唐某发现话费单上出现自己从未打过的长途电话,话费150余元,遂找电信局交涉,经查系电信局设备技术故障所致,唐某多次要求电信局作进一步解释并保证以后不再发生此类事情,电信局未予确认。
设循环队列的存储空间为Q(1:m),初始状态为front=rear=m。经过一系列正常的操作后,front=1,rear=m。为了在该队列中寻找值最大的元素,在最坏情况下需要的比较次数为
结构化程序设计主要强调的是()。
现在大家都有手机,很方便。但是因为不知道什么时候会有电话来,所以我睡觉或开会的时候就不开手机。我认为:
Publicspeakingfillsmostpeoplewithdread.Humiliationisgreatestfear;self-exposureandfailingtoappealtotheaudience
最新回复
(
0
)