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
专升本
A new kind of radar has been developed for spaceship travelers. A working laboratory model of a new system of radar that makes u
A new kind of radar has been developed for spaceship travelers. A working laboratory model of a new system of radar that makes u
admin
2012-11-20
62
问题
A new kind of radar has been developed for spaceship 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 used 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 (进入) 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 (对接) 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 could knock the station out of its orbit.
The light-beam radar, which operates at a frequency of trillions (百万兆) of cycles per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station. 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.
Laser-doppler radar ______.
选项
A、measures the movements of a spaceship by means of light beam
B、makes use of microwaves
C、makes use of sound waves
D、Both A and B
答案
A
解析
转载请注明原文地址:https://www.kaotiyun.com/show/JTeC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Shoppingforclothesisnotthe【61】experienceforamanasitisforawoman.Amangoesshoppingbecauseheneedssomething.Hi
TheMinisterofJusticehas______animmenseamountofcorrespondencebeforebreakfast.
Englandisnotabigcountry:fromnorthtosouthandfromeasttowestitisonlyaboutthreehundredmilesacross.Butforas
Wewalkedinsoquietlythatthenurseatthedeskdidn’tevenlifthereyesfromthebook.Mumpointedatabigchairbythedo
Itwasalmosttwoo’clock.Acoldwindhadcomeup,overthelake.Asablackcloudmovedacrossthesun,Walt,asmallboy,lo
Complainingaboutfaultygoodsorbadserviceisnevereasy.Mostpeopledislikemakingafuss.Butifsomethingyouhavebought
Complainingaboutfaultygoodsorbadserviceisnevereasy.Mostpeopledislikemakingafuss.Butifsomethingyouhavebought
Alovemarriage,however,doesnotnecessarily______muchsharingofinterestsandresponsibilities.
Insuranceisthesharingofrisks.Nearlyeveryoneisexposedtoriskofsomesort.Thehouseowner,forexample,knowsthathis
随机试题
关于掌握第一语言和第二语言的途径,正确的表述是
与硬膜外麻醉相比,蛛网膜下腔麻醉的特点是()。
金属烤瓷冠的金属基底冠有瓷覆盖部位的厚度一般为
下列哪一项不是肝郁气滞胁痛的特点( )。
我国规划体系的特征有()。
某单层工业厂房项目,檐高20m,建筑面积5800m2。施工单位在拆除顶层钢模板时,将拆下的18根钢管(每根长4m)和扣件运到井宇架的吊盘上,5名工人随吊盘一起从屋顶高处下落,此时恰好操作该机器的人员去厕所未归,一名刚刚招来两天的合同工开动了卷扬机。在卷扬机
金银首饰、钻石的消费税在生产销售环节征收。()
中央银行独立性的实质是如何处理中央银行和()的关系。
下列关于流动资产和流动负债的说法中,错误的是()。
Thepanelsalsotakeupspace.
最新回复
(
0
)