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
The making of glass is a very old industry—at least 4 500 years old. Glass has many extraordinary qualities and it is frequently
The making of glass is a very old industry—at least 4 500 years old. Glass has many extraordinary qualities and it is frequently
admin
2014-12-09
44
问题
The making of glass is a very old industry—at least 4 500 years old. Glass has many extraordinary qualities and it is frequently being used in new ways.
One of the most interesting new uses for glass is in telephone communication Scientists have developed glass fibres as thin as human hair which are designed to carry light signals. When the light reached the other end, it is first changed into electrical signals, which are in turn converted into sound messages.
Called light wave communication, the new system was used successfully in an experiment in Chicago in 1977. During the experiment, two glass fibres were able to carry 672 conversations at the same time. The lightwave cable, containing 144 glass fibres, has the capacity to carry 50 000 conversations at the same time.
The lightwave communication system has two important advantages. First, the glass fibre cables are smaller and weigh less than copper cables. Second, they cost less. Perhaps it can be said that telephone communication has entered the age of light.
From the passage, we can tell that people prefer glass fibre cables to copper cables because______.
选项
A、glass fibres are less expensive
B、glass fibres are easier to make
C、glass fibres deliver messages directly
D、glass fibres are more up to date
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/ARUC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
Lifeisnoteasy,soI’dliketosay"Whenanythinghappens,believeinyourself."WhenIwasayoungboy,Iwas【31】shytotalk
Bypoolingtheirresourcestogether,smallgroupsofstudentsgenerallygainadvantagesoverindividualswhoprefertostudyalo
Itisduringhissparetime______Johnsonhasbeenstudyingacourseinhistory.
Packagingisanimportantformofadvertising.Apackagecansometimesmotivatesomeonetobuyaproduct.Forexample,asmallc
Onceitwasconsideredgoodtokeepthecarengineidlingaminuteortwofollowingcoldstarts.Today,withmoderntechnology,
(非英语专业做)Therewasatimewhenparentswhowantedaneducationalpresentfortheirchildrenwouldbuyatypewriter,aglobe
Whatwillmanbelikeinthefuture—in5,000oreven50,000yearsfromnow?Wecanonlymakeaguess,ofcourse,butwecanb
IfherefusestopayIshalltake______againsthim.
Manyteenagersactagainsttheirparent’swishes.Ifwe【C1】______neatness,ourteenagerswillbesloppy(邋遢的).They’llleavethei
Menhavetraveledeversincetheyfirstappearedontheearth.Inprimitivetimestheydidnottravelforpleasurebuttofindn
随机试题
CT英文全称中“tomo”的含义是
将一叠文件分为若干组,每组正好有10份文件。已知其中2组文件中有18份通知。其余每组文件中最多有5份通知,且所有文件中通知占比正好为60%。那么这叠文件最多可能有多少份?
妊娠早期流产的主要原因是
预防肾盂肾炎最简单的措施是
患者可按处方和医嘱自行用药,社会药店可零售的处方药是患者不可自行用药,必须由医师使用或在医院由医师监控使用且社会药房不可零售的处方药是
在各种促销手段中,最有利于建立和培养友好关系,而且及时获得买主反应的方式是()。
Writeanessayof160-200wordsbasedonthefollowingdrawing.Inyouressay,youshould1)describethedrawingbriefly,
YouwillhearaspeechbyBobChase,PresidentoftheNationalEducationAssociation(NEA)totheAmericanAssociationofColleges
Itisastonishinghowlittleisknownabouttheworkingofthemind.Buthoweverlittleormuchisknown,itisfairlycleartha
OurcompanyoffersafullrangeofSmartHomeproducts,focusingonmakingyourhomesaferandmoreconvenient,andsavingenerg
最新回复
(
0
)