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 new kind of radar has been developed for space-age travelers. A working laboratory model of a new system of radar that makes u
A new kind of radar has been developed for space-age travelers. A working laboratory model of a new system of radar that makes u
admin
2015-12-31
26
问题
A new kind of radar has been developed for space-age travelers. A working laboratory model of a new system of radar that makes use of a beam of light is said to be ten thousand times more accurate than the best comparable system of radar that uses microwaves.
The model has shown that this radar system (known as laser-doppler radar) can measure with absolute precision speeds varying from spaceship orbital injection velocities (速度) of five miles per second down to virtual stops—speeds of less than one ten thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous (会合, 会合点) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ship’s skin, or a nudge (轻触) could knock the station out of its orbit.
The light-beam radar, which operates at a frequency of trillions of cycles per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station even at a small fraction of an inch per second. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.
This laser-doppler radar will be especially valuable in space because________.
选项
A、the speeds of space vehicles will vary greatly
B、accurate measurements are essential in space
C、inaccuracies in measurement could cause accidents in space
D、all of the above
答案
D
解析
文中第二段第二句、第三句说:“据正在开发这个系统的科学家说,这样精确的速度测量对于太空飞行来说是头等重要的事情。这种精确的速度测量的重要性在于,当处在两艘宇宙飞船的会合点上,或当一个飞行器在一个轨道太空站进行着陆时,一次轻微碰触就有可能把飞船的外壳撕开一个口子或把太空站撞出其运行轨道。”由此我们可以得出选项B和C都符合题意;又根据文中第二段第一句可知选项A符合题意。而选项D说A、B、C三个选项都对,故本题正确答案为D。
转载请注明原文地址:https://kaotiyun.com/show/Y7WO777K
0
在职攻硕英语联考
相关试题推荐
ThesharpfallincigaretteconsumptionintheUShasledtosteepdeclinesinsomenegativehealthoutcomes.Butithasalso,i
Thewriterregardsphysicalexerciseasastrongmedicinebecause______.Accordingtothepassage,regularphysicalexercisec
Wearesurethat______todothisfacetoface,hewouldfinditdifficulttoexpresshimselfwithoutlosinghistemper.
Howeverweakyourmemorymaybe,youcanmakeupforitby______whatyouwanttoremember,andrepeatingitoverandoveragai
Icouldn’t______thelectureatall.Itwastoodifficultforme.
TheUSFoodandDrugAdministration(FDA)istakingstepstoprotectthecountry’sbloodsupply.Peoplegivebloodtothecenter
Nowadaysitisnotuncommonforabig,strongschoolboytoelbowanelderlywomanasideinthedashforthelastremainingseat
Woman:AreyougoingtoHawaiionyourvacation?Man:Notthisyear.Iambroke.Woman:Oh!Comeon.Question:Howdoesthewom
Theterm"NewAustralians"cameintovogueinthe50sand60s,whichimpliedthatthegoalofimmigrationwasassimilationandt
______quiterecently,mostmothersinBritaindidnottakepaidworkoutsidethehome.
随机试题
《战国策》作为重要文献可以很好地研究()
循行于下肢外侧中线的经脉是
有关呕血与黑粪的描述,以下不正确的是
在房地产经纪机构的告示责任中,不必公示的内容是()。
静止油面(油面上为大气)下3m深度处的绝对压强为下列哪一项?()(油的密度为800kg/m3,当地大气压为100kPa)
施工项目总成本降低率计算公式为:设计预算成本计划降低率=设计预算总成本计划降低额/设计预算总成本,它属于成本计划的()。
中国公民赵某,在一家上市公司任职,2018年取得收入如下:(1)每月工资薪金12000元,12月份取得年度一次性奖金50000元。(2)10月份取得财政部发行国债的利息1200元,取得某国内上市公司发行的公司债券利息750元。(3)11月份赵某从A国
尽管人们急需更好的新型药物来治疗神经退行类疾病,但对大型制药公司来说,研发相关药物却过于复杂和昂贵,花费数百万美元的研发随时可能失败,投资风险巨大。因此,不能指望大型制药公司会投资研发治疗神经退行类疾病的药物。以下哪项为真,最能够反驳上述推理?(
某高校学生甲、乙在学校操场上打篮球时,乙投篮,球反弹将甲的头部砸伤。甲的损害应由()(2016年非法学基础课单选第31题)
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
最新回复
(
0
)