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
51
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.
Which of the following statements is implied but not stated?
选项
A、Microwave radar operates at a higher frequency than laser-doppler radar.
B、Laser-doppler radar is more accurate than microwave radar.
C、The light-beam radar can measure only slow speeds with absolute accuracy.
D、Microwave radar does not insure absolute precision in measuring varying speeds.
答案
D
解析
本题可通过排除法找到答案。从文中第一段第二句和第二段第一句可知,激光多普勒雷达系统比使用的微波雷达系统精确万倍,因此选项B在文中已提出,故可排除;同时根据文中第一段第二句可知,这种新型雷达系统尚在试验中,而已经使用的是微波雷达系统,因此选项A可排除;文中第二段第一句指出,这种激光雷达系统能够绝对精确地测量速度变量,因此选项C可排除。本题亦可通过综合推理法找到答案。文中在第一段第二句提到多普勒雷达系统比已经使用的微波雷达系统精确万倍,而在第二段中又举例说多普勒雷达能绝对精确地测量不同的速度。综合上述信息,我们可以推断出采用微波技术的雷达系统不能确保各种速度的精确测量。因而选项D正确。
转载请注明原文地址:https://kaotiyun.com/show/i7WO777K
0
在职攻硕英语联考
相关试题推荐
TheUnitedNationsWorldFoodProgramsays______(3words)couldpush100millionpeopleintohunger.
Irelandisthebestplaceintheworldtolivefor2005,【B1】______alifequalityrankingthatappearedinBritain’sEconomist
Woman:Whatdoyouliketodoonyoursummervacation?Man:Ilikenothingbetterthanfishingonahotsummerday.Question:What
Accordingtoaconcerned1997articleintheBostonGlobe,theUnitedStatesspentlessthanonepercentofitstransportationb
"Couchpotatoes"inParagraph1referstothosewho______.Apartfromtechnology,thegrowingleisuretimethroughoutthetwen
Theincreaseinhomehealthcare’aidsispartlydueto______.Graduatefromphysical-therapyeducationprograms______.
OnereasonwhymanyAmericansarestillfascinatedbythefrontieristhat______.Bysaying"Recently,Americanshavecometo
Alittlelearningisadangerousthing,foryoumightaswellnotknowathing______knowitonlyimperfectly.
Thepopulationexplosionwillleadto______.Urbanizationcancauseenvironmentalproblemsbecause______.
SpeakerA:Here’sagiftforyou.IboughtitinChina.SpeakerB:______
随机试题
少量钠、钾单质应保存在煤油中。
知觉是人脑对直接作用于感觉器官的事物的_______的反映。
现代医学伦理学中,对生命的看法已转变为
动物小说《第七条猎狗》的作者是()。
中国真正进入全球化的坐标体系,也就是在这短短三十多年,但就是在这三十多年里,我们写下了让世界________的“中国故事”。从________的革命年代,到________的建设岁月,再到________的改革时期,在不断探索和奋斗中,我们形成和发展了中国
对下列哪种情形应当附加适用剥夺政治权利刑?()
subwaysalmon
一袋10磅的新鲜土豆一般值2美元,而脱水的速食土豆平均每磅值3美元。可以得出结论,一些消费者为了方便愿意支付15倍的价格,因为这种方便食品的销量在持续增加。下列哪项如果正确,能够指出上述的论证有较大的缺陷?
下列不属于需求说明书应该包括部分的是__________。
Theindustrialagehasbeentheonlyperiodofhumanhistoryinwhichmostpeople’sworkhastakentheformofjobs.Theindustr
最新回复
(
0
)