土壤中的钾的形态?

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问题:

土壤中的钾的形态?

考点:肥料知识肥料知识题库
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流行性乙型脑炎的发病年龄主要在()

A.成年人

B.10岁以下的儿童

C.可通过母体传播给胎儿

D.年老体弱者

E.缺乏年龄特征

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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。

The style of the second paragraph is mainly()

A. factual

B. sarcastic

C. emotional

D. argumentative

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(一)
一批由同种原料织成的布,用5种不同的印染工艺处理后进行缩水率试验。已知每种印染做4次试验,并由测试结果计算得到方差分析的主要结果,如表2.1-7所示。

表2.1-7 方差分析表

来源偏差平方和自由度均方和FF0.95(4,15)

因子A

误差e

SA=46.24

Se=48.37

11.56

3.225

3.583.06
总计TST=94.6119

请根据表中数据分析下列问题:

因子A的显著性情况为( )。

A.在α=0.05不显著

B.在α=0.05显著

C.在α=0.95不显著

D.在α=0.95显著

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主要适用于中短期政府债券,特别是国库券发行的国债发行方式是( )。

A.承受法
B.支付发行法
C.出卖法
D.公募法

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发电车本车用电,控制屏有哪些控制功能?

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