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
2012-07-17
47
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 radar system is significant because it______.
选项
A、is more precise than microwave radar
B、will work on the earth’s surface as well as in space
C、is the first radar system to work in space
D、is easier to operate than microwave radar
答案
A
解析
参见上题题解。
转载请注明原文地址:https://www.kaotiyun.com/show/rbXO777K
0
在职攻硕英语联考
相关试题推荐
Thedifferencebetweenaliquidandagasisobvious【C1】______theconditionsoftemperatureandpressurecommonlyfoundatthes
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C1】______difficulty:someplannersbelievein【C2】____
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C1】______difficulty:someplannersbelievein【C2】____
Thestatesmanwasevidently______thejournalist’squestionsandglaredathimforafewseconds.
IntheUnitedStatesandinmanyothercountriesaroundtheworld,therearefourmainwaysforpeopletobe【C1】______aboutdeve
TheJapanesedesireformarriagehadbeenverystrong.Inthefifth""worldyouthattitudesurvey""【C1】______bytheManagementa
Othernon-dominantmaleswerehyperactive;theyweremuchmoreactivethanisnormal,chasingothersandfightingeachother.
Today,theTowerofLondonisoneofthemostpopulartourist【C1】______andattractso-verthreemillionvisitorsayear.Itwas
ThehistoryofAfrican—Americansduringthepast400yearsistraditionallynarrated【C1】______anongoingstruggleagainst【C2】___
PsychologistAlfredAdlersuggestedthattheprimarygoalofthepsyche(精神)wassuperiority.Although【C1】______hebelievedthati
随机试题
女,65岁。慢性咳喘15年,间断性下肢水肿2年。查体:BP120/80mmHg,颈静脉怒张,左下肺可闻及干湿啰音,心界向左扩大,P2>A2,三尖瓣区可闻及3/6级杂音。肝肋下3cm。与上述诊断符合的心脏改变是()
伤寒杆菌从肠道感染后进入血液通过
涂膜防水层的耐用年限取决于:[2011年第57题]
在10/0.4kV变压器为电动机供电时,当系统短路容量是变压器容量的50倍以上时,笼型电动机全压直接经常启动的最大电动机额定功率不宜大于电源变压器容量的多少()
入境尸体、棺柩、骸骨的报检,报检人应向检验检疫机构提供( )。
爱国主义教育在我国中小学德育的内容中属于()范畴。
中国早期接受宣传马克思主义的主要是()。
[*]
在窗体上画一个名称为Command1的命令按钮,编写如下事件过程:PrivateSubCommandl_Click()n=0Fori=0To10X=2*i-1TfXMod3=0Thenn
DuringtheH1N1flupandemic(流行病),schoolsclosed,healthofficialsencouragedhandwashingandwarnedpregnantwomentogetvac
最新回复
(
0
)