首页
登录
职称英语
The railroad industry could not have grown as large as it did without steel. The
The railroad industry could not have grown as large as it did without steel. The
游客
2023-07-13
45
管理
问题
The railroad industry could not have grown as large as it did without steel. The first rails were made of iron. But iron rails were not strong enough to support heavy trains running at high speeds. Railroad executives wanted to replace them with steel rails because steel was ten or fifteen times stronger and lasted twenty times longer. Before the 1870’s, however, steel was too expensive to be widely used. It was made by a slow and expensive process of heating, stirring, and reheating iron ore.
Then the inventor Henry Bessemer discovered that directing a blast of air at melted iron in a furnace would burn out the impurities that made the iron brittle (易碎的). As the air shot through the furnace, the bubbling metal would erupt in showers of sparks. When the fire cooled, the metal had been changed, or converted, to steel. The Bessemer Converter made possible the mass production of steel. Now three to five tons of iron could be changed into steel in a mater of minutes.
Just when the demand for more and more steel developed, prospectors, discovered huge new deposits of iron ore in the Mesabi Range, a 120-mile-long region in Minnesota near Lake Superior. The Mesabi deposits were so near the surface that they could be mined with steam shovels.
Barges and steamers carded the iron ore through Lake Superior to depots (车站) on the southern shores of Lake Michigan and Lake Erie. With dizzying speed, Gary, Indiana, and Toledo, Youngstown, and Cleveland, Ohio, became major steel-manufacturing centers. Pittsburgh was the greatest steel city of all.
Steel was the basic building material of the industrial age. Production skyrocketed from seventy-seven thousand tons in 1870 to over eleven million tons in 1900. [br] According to the passage, the railroad industry preferred steel to iron because steel was ______.
选项
A、cheaper and more plentiful
B、lighter, and easier to mold
C、cleaner, and easier to mine
D、stronger and more durable
答案
D
解析
第一段第3句:铁路部门希望用钢轨来代替铁轨,因为钢比铁坚固10—15倍,使用寿命是铁的20倍
转载请注明原文地址:https://tihaiku.com/zcyy/2832426.html
相关试题推荐
[originaltext]AContinentalPacificRailroadgoodstrainderailed(wentoff
[originaltext]AContinentalPacificRailroadgoodstrainderailed(wentoff
[originaltext]Thereseemsnevertohavebeenacivilizationwithouttoys,b
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
Memoryisourmostimportantpossession.Withoutmemory,youwouldn’tknoww
[originaltext]Weuseallsortofserviceswithoutthinkingabouthowweget
随机试题
IntheUnitedStates,thefirstdaynurserywasopenedin1854.Nurserieswe
Ahappymarriageapparentlyisgoodmedicine,buthostilespousesmaybehar
在面向对象分析过程中,用概念模型来详细描述系统的问题域,用(作答此空)来表示概念
治疗阴虚肝旺型子晕,应首选的方剂是()A.一贯煎 B.麦味地黄丸 C.
布卢姆认为,完整的教育目标分类包括三个主要领域:一是_____的;二是_____
某事故经调查发现,主要是由于勘察过程中地基承载能力估计错误造成的。按照事故产生的
CA19-9常用于的诊断A.肝癌B.卵巢癌C.胃癌D.结直肠癌E.胰腺癌
《美国药典》的英文缩写是A.ChP B.USP C.BP D.JP E.
金融期货的交易对象是()。A:外汇B:金融期货合约C:债券D:股票
反映组成该项目的所有工作任务的组织工具是()。A.项目结构图 B.管理职能分工
最新回复
(
0
)