患者男，40岁，确诊为急性胰腺炎，内科正规治疗2周后体温仍38～39℃，左上腹压痛明

原核细胞和真核细胞最明显的区别在于[ ]

A．有无核物质

B．有无细胞壁

C．有无核膜

D．有无细胞膜

工程项目实施阶段，做好对( )是工程资源节约的主要途径。

A．工、料、机的计划与控制
B．工人的管理
C．材料的管理
D．机械的管理

下列原始凭证属于自制原始凭证的是( )。

A．购入材料后，验收入库时填写的收料单

B．增值税专用发票

C．出差购买的机票

D．支付过桥费的收费收据

We often think of future. We often wonder __1________ the world will be like in a hundred years’ time.

Think ___2_____ space. Perhaps a permanent station on the moon ___3_____ (set up). Perhaps people will be able to visit the moon as __4______. Cheap rockets for space travel will have been developed, __5______ (permit) long journeys through the solar system. When that time comes, people will be taking holidays in space and visiting __6_______ planets. Great progress will have been made _____7___ medicine, too. Pollution will have been controlled in a hundred years’ time.

__8________ the world will have been developed — even Antarctica. We will have used up most of the earth’s land to build our cities; __9_______ floating cities will have been built. The Japanese have already had plans of this kind. And there will be cities __10______ the sea.

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。

According to the text, the author mentions plutonium in paragraph 1 to（）

A. estimate the amount of nuclear material in Europe

B. exemplify one of the possible causes of lung cancer

C. highlight the measures needed to prevent lung cancer

D. show the destructive properties of industrial waste materials