问题 选择题

工业上将赤铁矿炼成铁是一个复杂的过程,炼铁高炉中发生的主要反应有(  )

①C+O2CO2②Fe2O3+3H22Fe+3H2O

③Fe2O3+3CO2Fe+3CO2

④2Fe2O3+3C4Fe+3CO2

⑤CO2+C2CO

A.②③⑤

B.①③⑤

C.①④⑤

D.②③

答案

答案:B

把铁矿石和焦炭、石灰石一起加入高炉,在高温下焦炭与过量的空气生成CO2,同时放出大量热供给炼铁使用,在高温条件下,二氧化碳与过量焦炭反应生成CO,一氧化碳与赤铁矿(主要成分是Fe2O3)反应生成铁。

单项选择题

The landscape of the Giant’s Causeway, lurking below the gaunt sea wall where the land ends, must have struck wonder into the hearts of the ancient Irish, who subsequently felt inspired and created legends about its builder: the giant Finn McCool. The Causeway Coast has an unparalleled display of geological formations representing volcanic activity during the Early Tertiary Period some 5060 million years ago. Its Tertiary lavas of the Antrim Plateau, covering some 3,800 sq km, represent the largest remaining lava plateau in Europe.
The Causeway is a mass of basalt columns packed tightly together. The tops of the columns form stepping stones that lead from the cliff foot and disappear under the sea. Altogether there are 40, 000 of these stone columns, mostly hexagonal, but some are quadrangular, pentagonal, heptagonal and octagonal. The tallest ate about 40 feet high, and the solidified lava in the cliffs is 90 feet thick in places.
A fine circular walk will take you down to the Giant’s Causeway, past amphitheatres of stone columns and formations with fanciful names like the Honeycomb, the Wishing Well, and the Giant’s Granny, past a wooden staircase to Benbane Head, and back along the cliff-top. Further down the coast, the stunning Carrick-a-rede rope bridge spans a gaping chasm between the coast and a small island used by fishermen. The eighty-foot drop can be crossed via the swinging bridge—and is not for the faint-hearted!
The Giant’s Causeway and Causeway Coast site was inscribed as a World Heritage Site by UNESCO in 1986. The site is of outstanding universal value and meets the criteria set in the World Heritage Convention. Namely, it is an outstanding example representing major stages of the earth’s history including the record of life: significant on-going geological processes in landform developments, and significant geomorphic and physiographic features; moreover, it also contains superlative natural phenomena and areas of exceptional natural beauty and aesthetic importance.
Moyle District Council’s Causeway Visitor Centre is open daily all year round and located on the cliff top 1 km from the site. The Centre is the ideal starting point for walks along the coastal and cliff-top paths, providing all excellent range of visitor services. A 12-minute audio-visual presentation, with commentary available in 5 European languages, enables visitors to further explore the origins of the Giant s Causeway through local folklore and scientific theory, and highlights the many other attractions of the Causeway Coast and Glens of Antrim area.

Which of the following is NOT true of the Giant’s Causeway

A.It provides visitors grand and breath-taking views.

B.It is a source of literary inspiration for the ancient Irish.

C.It serves as an excellent piece of material for scientific research.

D.It dwarfs many other World Heritage Sites in Europ

单项选择题