某学者在某地进行吸烟与肺癌关系的研究,结果显示,该地人群肺癌年死亡率为0.56‰,吸

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问题:

某学者在某地进行吸烟与肺癌关系的研究,结果显示,该地人群肺癌年死亡率为0.56‰,吸烟与不吸烟者的肺癌年死亡率为0.96‰和0.07‰。上述研究的人群归因危险度百分比为()。

A.0.40‰

B.0.89‰

C.92.7%

D.87.5%

E.0.49‰

考点:健康教育与健康促进(医学高级)流行病学流行病学题库
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电阻R1和R2串联后接在电压为9V的电源上,通过R1的电流是0.4A,R2的阻值为10Ω。求:(1)R2两端的电压U(2)R1两端的电压U1(3)R1的阻值。

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已知点A(1,2a+2)到x轴的距离是到y轴距离的2倍,则a的值为     

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Electrical devices(仪器)could soon use power make by human energy. Scientists say they have developed an experimental device that produces electricity from the physical movement of a person walking . British scientist Max Donelan and other scientists in Canada and the United States developed the device.

The device connects to a person’s knee. As the person walks, the device captures energy each time the person slows down. To do this , the device helps with the slowing sown movement of the leg.  The movements of the walking person push parts of a small machine that produces electricity. Using the device, an adult walking quickly could produce thirteen watts of electricity in just a minute. Donelan says walking at that speed could produce enough power to operate a laptop computer for six minutes.

There are several possible uses for the device . Developers say it could help people who work in areas without electricity to operate small computers. The device could also be used in hospitals to operate heart pacemakers(起博器). It could even be used to assist in the movement of robotic arms and legs.

The experimental version of the device weighs about one and a half kilograms, but it is too costly for most people to buy. But the researchers hope to make a lighter, less costly version. An improved version should be ready in one year.

The developers hope the device will one day help developing countries. Nearly twenty five percent of people around the world live without electric power.

A similar product was invented in 2005 by Larry Rome of the University of Pennsylvania. He created a bag carried on a person’s back that also produces power from walking. The knee device does not produce as much electricity as the bag . But the bag requires the walker to carry a load of twenty to thirty kilograms.

小题1:The second paragraph mainly talks about       .

A.who developed the device

B.how the device works

C.several possible uses for the devices

D.how much electricity the device can produce小题2:What is the disadvantage of the experimental version of the device?

A.It is too heavy for the walker to bear

B.It is too complex for people to use

C.It is too expensive for most people to afford

D.It will slow down one’s walking speed.小题3:Compared with the device designed by Larry Rome ,this new device       .

A.produces power without adding more loads to the walker

B.can produce more power in a much shorter time

C.needs to be equipped with a battery

D.can help the walker walk faster小题4:From the passage, we can learn that the electrical device can       .

A.help housewives operate the washing machine

B.make it much easier for us to go online

C.produce more electricity than that invented by Larry Rome

D.be applied to operate heart pacemakers小题5:What would be the best title for the passage?

A.First device powered by walking will soon be on the market

B.Advanced technology brings in a new way to operate heart pacemakers

C.Device gives new meaning to the idea of power walking

D.Human energy will become a main source of electricity

题型:单项选择题

我国现行版药典是()

A.2000年版

B.2003年版

C.2005年版

D.2008年版

E.2010年版

题型:单项选择题

干部必须具有下列哪些条件。()

A.胜任本职工作所必需的理论、政策水平

B.现代军事、科学文化、专业知识

C.经过院校培训并取得相应学历,组织、指挥能力

D.身体健康

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