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
2023-09-03
37
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; 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、Workers on the platforms and trains were replaced by machines.
B、A completely automatic line was added to its network.
C、It became the first completely automatic railway in the world.
D、Its trains became manual-controlled.
答案
B
解析
What happened to the complete London underground railway thirty-nine years ago?
转载请注明原文地址:https://tihaiku.com/zcyy/2981744.html
相关试题推荐
[originaltext]Evenatschooltherehadbeenanunhealthycompetitionbetwee
[originaltext]Evenatschooltherehadbeenanunhealthycompetitionbetwee
[originaltext]Evenatschooltherehadbeenanunhealthycompetitionbetwee
[originaltext]M:Andnow,Mrs.Smith,canyoutelluswhathappenedatyourapa
[originaltext]M:Andnow,Mrs.Smith,canyoutelluswhathappenedatyourapa
[originaltext]M:Andnow,Mrs.Smith,canyoutelluswhathappenedatyourapa
[originaltext]W:Tellmealittlebitaboutyourself,please.M:MynameisDav
[originaltext]W:Tellmealittlebitaboutyourself,please.M:MynameisDav
[originaltext]Readingtooneselfisamodernactivitywhichwasalmostunkn
[originaltext]Readingtooneselfisamodernactivitywhichwasalmostunkn
随机试题
Urbancenterswithstrongteleconnectivityneedfewervolunteersthanremoteare
Ifyouexplainedthesituationtoyoursolicitor,he______abletoadviseyoum
TheDoctorWillSkypeYouNowA)Faz
干粉灭火系统应对减压阀应定期进行圧力试验,观察二次压力是否符合定值。
共用题干 患者,男性,58岁,体检时B超显示肝部有肿块,血化验发现癌胚抗原升高
防火分隔设施是指能在一定时间内阻止火焰蔓延,把整个建筑内部空间划分成若干个较小防
A.12 B.-6 C.-12 D.0
合同订立后未生效,需要权利人追认才能生效的合同是()。A.效力待定的合同 B
学生心理发展的特征
下列合同文件中,属于《标准施工招标文件》中施工合同文本的合同文件,在专用条款没有
最新回复
(
0
)