首页
登录
职称英语
What happened to the London underground railway about three decades ago? [br] [
What happened to the London underground railway about three decades ago? [br] [
游客
2023-11-22
41
管理
问题
What happened to the London underground railway about three decades ago? [br]
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 of 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. If one train stays 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、A platform worker.
B、The command spot.
C、A computer.
D、A machine.
答案
D
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3210514.html
相关试题推荐
Thenewundergroundrailwaywill______thejourneytoallpartsofthecity.A、co
BythetimeyougettoNewYork,I______forLondon.A、wouldbeleavingB、amleav
DecadesbeforetheAmericanRevolutionof1776,JesseFish,anativeNewYo
They______uswillinglybutthattheyhappenedtobeshortofhands,too.A、would
Videorecordersandphotocopiers,eventicketmachinesontherailway,often
Videorecordersandphotocopiers,eventicketmachinesontherailway,often
The______crownjewelsarekeptintheTowerofLondon.A、valuedB、valuelessC、i
Whathappenedafterthemanbuilthisfirstcomputer?[br][originaltext]Maggie
WhathappenedtotheLondonundergroundrailwayaboutthreedecadesago?[br][
WhathappenedtotheLondonundergroundrailwayaboutthreedecadesago?[origin
随机试题
Indiaistofrugality(节俭)asBethlehemistoJesus.Asrichcountriesentera
在施工现场的防火巡查中,发现(),应当上报有关领导,制定限期改正措施。A.在建
关于横线①处所用文种的说法,错误的是()。 A.适用于向上级机关行文 B.使
网络表演经营单位从事网络表演经营活动未申请许可证的,由县级以上文化行政部门或者文
公路平面交叉中,()公路的平面交叉应进行渠化设计。A.一级 B.二级 C.
A.IgA B.sIgA C.IgG D.IgM E.IgE由唾液腺分泌
上市公司公开发行股票,以下构成障碍的有()。A、上次非公开发行,当年营业利润下降
根据巴塞尔协议Ⅱ,第一支柱资本充足率覆盖的风险类型包括()。A.信用风险 B
点M(1,2,1)到平面x+2y+2z=10的距离是()。 A.
(2016年真题)砌石路基的砌石高度最高可达()。A.5m B.10m C.
最新回复
(
0
)