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、Because it is designed like a cradle. B、Because it is pulled and pushed by magnetic attraction and repulsion. C、Because it run
A、Because it is designed like a cradle. B、Because it is pulled and pushed by magnetic attraction and repulsion. C、Because it run
admin
2013-06-03
73
问题
What does maglev look like? Japanese engineers designed a vehicle that runs in a cradle-like track or guideway. Magnetic attraction and repulsion pull and push maglev forward. To stop the trains, the magnetic force is reversed, much like airplanes are stopped by reversing the force of the engines. Both types of maglev are quiet, fast, and save. Since maglev rides on air, there is no friction between wheels and rails to make noise or to slow it down. If the external power fails, there is a battery-operated system on the train itself that takes over and brings the cars to a smooth stop.
Maglev could be the answer to our problems. It could become the typical short and middle-distance mass transportation system of the twenty-first century. If it does, we will enjoy many benefits. We will ride in save, fast, quiet trains between cities up to about 500 miles apart in less time than it takes to fly if you include the time for ground transportation. We will conserve precious land because maglev can be built where railroads run, down the middle of existing super-highways or elevated above existing streets and roads. And we will probably save money, too. According to a German estimate, a mile of two-way track will cost about nine million dollars whereas a mile of interstate highway costs about 25 million dollars in the United States.
选项
A、Because it is designed like a cradle.
B、Because it is pulled and pushed by magnetic attraction and repulsion.
C、Because it runs on air.
D、Because there’s no friction between wheels and rails.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/lvg7777K
0
大学英语四级
相关试题推荐
A、Theindividualcitizenscontrol.B、Theindividualstatescontrol.C、Thecountrycontrols.D、Individualcitiesorvillagecontr
Rumoristhemost【C1】______wayofspreadingstories---bypassingthemonfrommouth【C2】______month.Butcivilizedcountriesinn
Rumoristhemost【C1】______wayofspreadingstories---bypassingthemonfrommouth【C2】______month.Butcivilizedcountriesinn
Rumoristhemost【C1】______wayofspreadingstories---bypassingthemonfrommouth【C2】______month.Butcivilizedcountriesinn
A、Foodprocessing.B、Environmentalprotection.C、Shoppinghabits.D、Over-packagingproblems.B
A、Dialingthenumberagain.B、Havingthephonerepaired.C、Leavingamessageonphone.D、Sendingane-mail.C关键字眼处设题。男士说Alice的电话
A、Becauseherparentsdonotforcehertodowhatshedoesn’twanttodo.B、BecauseherparentsallowhertostudyinEngland.C
A、Sheisn’thavingmuchtrouble.B、Sheunderstoodthereadingyesterday.C、Sheunderstandsverylittle.D、Sheisgoodatintensi
Ifthediverisindeepwater,hemustcometothesurfaceinordertoallowhisbodyto______tothechangeinpressure.
Consumersarebeingconfusedandmisledbythehodge-podge(大杂烩)ofenvironmentalclaimsmadebyhouseholdproducts,accordingt
随机试题
有以下程序#include<stdio.h>main(){printf("%d\n",NULL);}程序运行后的输出结果是
手正位摄影的中心线应对准
男孩,4岁,因怀疑先天性心脏病就诊。合并症治愈后,进一步治疗的方法为
A.噻吗洛尔B.曲伏前列素C.溴莫尼定D.地匹福林E.毛果芸香碱具有缩小瞳孔和降低眼压作用的拟M胆碱药是()。
肺结核患者在家里休养治疗期间,简便有效的处理痰液的方法是
图示刚架中,若将作用于B处的水平力P沿其作用线移至C处,则A、D处的约束力:
我国增值税征税范围为()。
会计主体与法律主体是两个对等的概念。()
ABC会计师事务所拟为A公司提供20×8年财务报表审计业务,在考虑沟通问题时遇到以下事项,请代为做出正确的专业判断。(假设A公司20×7年度财务报表由EFG会计师事务所审计)
项目出现了严重的缺陷,项目经理将项目团队和质量工程师召集在一起分析问题,查找原因,大家就此提出了三种不同的看法。此时宜采用()工具或方法来确定问题的根本原因。
最新回复
(
0
)