题目
A.Copper
B.Iron
C.Compound
D.Quartz
第1题
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.
According to the passage, the railroad industry preferred steel to iron because steel was ______.
A.cheaper and more plentiful
B.lighter, and easier to mold
C.cleaner, and easier to mine
D.stronger and more durable
第2题
A.the dura mater,the arachnoid,the pia mater
B.the dura mater,the pia mater,the arachnoid
C.the pia mater,the arachnoid,the dura mater
D.the pia mater,the dura mater,the arachnoid
E.the arachnoid,the pia mater,the dura mater
第3题
A.scarcely
B.eventually
C.previously
D.exactly
第4题
第5题
A.NameNode
B.DataNode
C.SecondaryNamenode
D.本地硬盘
第8题
A.No matter how
B.No mater what
C.What ever
D.Whether or not
为了保护您的账号安全,请在“赏学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!