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
外语
A、The workers on the underground platforms were replaced by machines. B、It became the first completely automatic railway in the
A、The workers on the underground platforms were replaced by machines. B、It became the first completely automatic railway in the
admin
2013-01-22
37
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:https://jikaoti.com/ti/S8kFFFFM
0
大学英语六级
相关试题推荐
Spaceisadangerousplace,notonlybecauseofmeteors(流星)butalsobecauseofraysfromthesunandotherstars.The【26】again
A、Itisagiftgivenbyothers.B、Thereisnowaytoincreaseit.C、Itdependsonwhatwecanorcannotdo.D、Itispartofthe
12ThingsI’veLearnedFromTravelingAroundtheWorldforThreeYearsOnMarch13,2007,Ihandedoverthekeystomyhouse
12ThingsI’veLearnedFromTravelingAroundtheWorldforThreeYearsOnMarch13,2007,Ihandedoverthekeystomyhouse
12ThingsI’veLearnedFromTravelingAroundtheWorldforThreeYearsOnMarch13,2007,Ihandedoverthekeystomyhouse
A、ThemanhasdecidedtochooseLanguageStudiesashismajor.B、Thewomanisn’tinterestedinthepsychologyoflanguage.C、The
Dogsareoftenpraisedfortheir______;theyalmostneverabandontheirmasters.
A、Teenagersshouldgotoseepsychologistfrequently.B、Peopleshouldmakeasmanyfriendsaspossible.C、Policymakersshouldc
A、Heisthegirl’sfriend.B、Heisthegirl’sfather’soldfriend.C、Heisthegirl’steacher.D、Heisthegirl’suncle.BM:You
A、Heisnotaqualifiedteacher.B、Hehasalreadybeenmarried.C、Hedoesnotfeellikegoingtothedinner.D、Hedoesnotknow
随机试题
某承包人为了赶工期,曾在雨中铺筑沥青混凝土,对此造成的质量缺陷,监理工程师应()。
下列句子表述得体的一项是()
在肠外营养支持疗法中,不属于外周静脉途径的禁忌证的是
男性,30岁,急性阑尾炎,医生检查时病人取左侧卧位后,使其右下肢向后过伸,引起右下腹疼痛此项检查称为
慢性胃炎的饮食护理中哪项应除外
甲国有企业拟利用英国乙公司的投资将其全资拥有的丙国有独资公司(下称丙公司)改组为中外合资经营企业。甲企业在与乙公司协商后,拟订的有关改组方案中有关要点如下:(1)改组前的丙公司注册资本5000万元人民币。甲企业拟将丙公司60%的股权转让给乙公司,转让价款
列各项中,符合房产税纳税义务发生时间规定的有()。(2008年)
在天气、土壤、水域、生物受到严重污染的城市,工矿区以及河流与沿海地带多为各种环境性疾病的发病区。当代城市的“三废”污染与支气管炎、肺气肿、肺癌、食道癌、肠癌、胃癌和心血管疾病的发病率有着密切的关系。这段话主要支持的一种观点是()。
在旅游者途经和逗留的地方构成接待群体的居民,有权得到旅游者对他们的习俗、宗教和文化的理解和尊重,因为这些都属于人类的共同遗产。他们有权自由地使用自己的旅游资源,同时通过他们的态度和行为,使他们的自然和文化环境得到尊重。为了对这样的理解和尊重提供便利,旅游者
有三个进程PA、PB和PC合作解决文件打印问题:PA将文件记录从磁盘读入主存的缓冲区l,每执行一次读一个记录;PB将缓冲区1的内容复制到缓冲区2,每执行一次复制一个记录;PC将缓冲区2的内容打印出来,每执行一次打印一个记录。缓冲区的大小等于一个记录的大小。
最新回复
(
0
)