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
2024-10-31
1
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、To drive the train after it is started automatically.
B、To start the train and to drive it when necessary.
C、To take care of the passengers on the train.
D、To send commanding signals to the command spot.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3825083.html
相关试题推荐
Whathappenedafterthemanbuilthisfirstcomputer?[br][originaltext]Maggie
WhathappenedtotheLondonundergroundrailwayaboutthreedecadesago?[br][
IhaveneverbeentoLondon,butthatisthecity______.A、whereIliketovisit
Videorecordersandphotocopiers,eventicketmachinesontherailway,ofte
JameswasborninLondon________May7,1952________4:45________themorning
Afewweeksago,Ihada【C1】______unusualflightfromLondontoKhartoum.
Afewweeksago,Ihada【C1】______unusualflightfromLondontoKhartoum.
Afewweeksago,Ihada【C1】______unusualflightfromLondontoKhartoum.
Afewweeksago,Ihada【C1】______unusualflightfromLondontoKhartoum.
Afewweeksago,Ihada【C1】______unusualflightfromLondontoKhartoum.
随机试题
Theoldestandsimplestmethod,then,ofdescribingdifferencesinpersonali
Ifyou【C1】______tobeginanewjobtomorrow,youwouldbringwithyousome
Theestimatesofthenumbersofhome-schooledchildrenvarywidely.TheU.S
A. B. C. D.
IPmulticastingisasetoftechnologies
疑有食管异物,在X线检查时,下列说法错误的是:()A.食管异物最易停留在
A.氯丙嚷 B.吗啡 C.苯妥英钠 D.地西泮(安定) E.苯巴比妥可控
建设单位应当将大型的人员密集场所和其他特殊建筑工程的消防设计文件报送公安机关消防
所谓“异地加工贸易”,是指加工贸易企业将保税料件加工的产品结转至另一直属海关关区
在疾病三级预防中,一级预防的重点是A.避免接触致病因素,提高机体抗病能力 B.
最新回复
(
0
)