试题与答案

客货共线铁路验收标准是与行车速度等条件有密切关系的质量指标,它是按时速()客货共线铁

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题目:

客货共线铁路验收标准是与行车速度等条件有密切关系的质量指标,它是按时速()客货共线铁路确定的。

A.100km

B.120km

C.140km

D.160km

答案:

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题型:填空题

A、B均为重要的有机化工原料。

已知:

请回答下列问题:

(1)A分子内含有苯环,其名称是         

(2)B分子中只有一种氢原子,2 mol B反应生成1 mol C的化学方程式是:

                                                                 

(3)B的一种同分异构体能发生银镜反应,该反应的化学方程式是:

                                                                      

(4)D分子内有3个甲基,其结构简式是                                   

(5)F的结构简式是                      。F和L反应生成G是加成反应,L的结构简式                             

(6)A与B反应生成J的化学方程式是                                        

(7)K分子内含有六元环,可发生水解反应,其结构简式是                      

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题型:单项选择题

When Dr. John W.Gofman, professor of medical physics at the University of California and a leading nuclear critic, speaks of "ecocide" in his adversary view of nuclear technology, he means the following: A large nuclear plant like that in Kalkar, the Netherlands, would produce about 200 pounds of plutonium each year. One pound, released into the atmosphere, could cause 9 billion cases of lung cancer. This waste product must be stored for 500,000 years before it is of no further danger to man. In the anticipated reactor economy, it is estimated that there will be 10,000 tons of this material in Western Europe, of which one table-spoonful of plutonium-239 represents the official maximum permissible body burden for 200,000 people. Rather than being biodegradable, plutonium destroys biological properties.

In 1972 the U.S. Occupational Safety and Health Administration ruled that the asbestos level in the work place should be lowered to 2 fibers per cubic centimeter of air, but the effective date of the ruling has been delayed until now. The International Federation of Chemical and General Workers’ Unions report that the 2-fiber standard was based primarily on one study of 290 men at a British asbestos factory. But when the workers at the British factory had been reexamined by another physician, 40--70 percent had X-ray evidence of lung abnormalities. According to present medical information at the factory in question, out of a total of 29 deaths thus far, seven were caused by lung cancer. An average European or American worker comes into contact with six million fibers a day. "We are now, in fact, finding cancer deaths within the family of the asbestos worker," states Dr. Irving Selikoff, of the Mount Sinai Medical School in New York.

It is now also clear that vinyl chloride, a gas from which the most widely used plastics are made, causes a fatal cancer of the blood-vessel cells of the liver. However, the history of the research on vinyl chloride is, in some ways, more disturbing than the "Watergate cover-up." "There has been evidence of potentially serious disease among polyvinyl chloride workers for 25 years that has been incompletely appreciated and inadequately approached by medical scientists and by regulatory authorities," summed up Dr. Selikoff in the New Scientist. At least 17 workers have been killed by vinyl chloride because research over the past 25 years was not followed up. And for over 10 years, workers have been exposed to concentrations of vinyl chloride 10 times the "safe limit" imposed by Dow Chemical Company. (422 words)

Notes: plutonium 钚。asbestos 石棉。polyvinyl chloride 聚氯乙烯。

By "ecocide" the author most probably means()

A. waste utilization

B. ecological balance

C. radioactive reaction

D. massive bio-destruction

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