首页
登录
职称英语
[originaltext] The world’s first completely automatic railway has been built
[originaltext] The world’s first completely automatic railway has been built
游客
2024-05-13
36
管理
问题
The world’s first completely automatic railway has been built under the busy streets of London. The railway is called the Victoria Line, and it is part of the complete London underground railway. The new Victoria Line was opened in 1969. This new line was very different from the others. The stations on the other lines need a lot of workers to sell tickets, and to check and to collect them when people leave the trains.
This is all different on the Victoria Line. Here a machine checks and collects the tickets, and there are no workers on the platforms.
On the train, there is only one worker. If necessary, this man can drive the train. But usually he just starts it; and it runs and stops by itself. The trains are controlled by electrical signals which are sent by the so-called "command spots".
The command spots are the same distance apart. Each sends a certain signal. The train always moves at the speed that the command spots allow. If the command spot sends no signals, the train will stop. Most of the control work is done by computers. The computers also fix the train’s speeds, and send the signals to the command spots. Other machines make sure that the trains are always a safe distance apart. One train may stay too long at a station; the other trains will then automatically move slower. So there is no danger of accidents on the line.
选项
A、The workers on the underground platforms were replaced by machines.
B、It became the first completely automatic railway in the world.
C、A completely automatic line was added to its network.
D、Computers began controlling the trains on the line.
答案
C
解析
What happened to the London underground railway?
转载请注明原文地址:http://tihaiku.com/zcyy/3597114.html
相关试题推荐
[originaltext]Ofthethousandsofdifferentkindsofanimalsthatexistin
[originaltext]Ofthethousandsofdifferentkindsofanimalsthatexistin
[originaltext]W:Well,weheardsomepeoplejustnowwhoseemtofeelthatothe
[originaltext]W:Well,weheardsomepeoplejustnowwhoseemtofeelthatothe
[originaltext]M:Willthatbecashorcharge?W:IwanttopaybycheckifIma
[originaltext]M:Willthatbecashorcharge?W:IwanttopaybycheckifIma
[originaltext]M:Willthatbecashorcharge?W:IwanttopaybycheckifIma
[originaltext]Americansaresufferingfromaserioussleepdeficitwhileal
[originaltext]Americansaresufferingfromaserioussleepdeficitwhileal
[originaltext]W:Icometoremindyouofameetingscheduledfor10o’clockthi
随机试题
[originaltext]IamanAmericanstudentlearningChineseinShanghai.During
Peoplewhoarehitbylightningandsurviveoftenhavelong-termeffects.Thes
Teenagersareunderalotofpressuretobethin.Theyareledtobelievetha
[originaltext]Thediamondisconsideredthemostfamousandvaluablejewel
[originaltext]Hello,everybody.WhatIwanttotalkabouttodayisanidea
【B1】[br]【B3】A、nativeB、humanC、physicalD、animalD逻辑关系及词义辨析题。句中说mall有别于theres
女性,28岁,第1胎,孕37周合并妊娠期高血压病,血压20/15kPa(150/
A.淀粉酶B.激肽酶C.胰蛋白酶原D.糜蛋白酶原E.蛋白酶血清淀粉酶降低可见于
我国近代制度化教育兴起的标志是( )。A.京师大学堂 B.学堂的出现 C.
下列哪项是充血性心力衰竭时血流动力学异常的特点A.心排血量下降,心室舒张末压力增
最新回复
(
0
)