2014年6月大学英语四级复习题及答案(第二套)_第3页

　　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. 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 matter 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?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 carried the iron ore through Lake Superior to depots 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.

　　31.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

　　?32.According to the passage, how did Bessemer method make the mass production of steel possible?

　　?A.It directed air at melted iron in a furnace, removing all impurities.

　　?B.It slowly heated iron ore then stirred it and heated it again.

　　?C.It changed iron ore into iron which was a substitute for steel.

　　?D.It could quickly find deposits of iron ore under the ground.

　　?33.According to the passage, where were large deposits of iron uncovered?

　　?A.In Pittsburgh. ?B.In the Mesabi Range.

　　?C.Near Lake Michigan.?D.Near Lake Erie.

　　?34.The words “Barges and steamers” could best be replaced by which of the following?

　　?A.Trains.B.Planes.?C.Boats.?D.Trucks.

　　?35.It can be inferred from the passage that the mass production of steel caused ____.

　　?A.a decline in the railroad industry

　　?B.a revolution in the industrial world

　　?C.an increase in the price of steel

　　?D.a feeling of discontent among steel workers