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问题 单项选择题

不符合高渗性非酮性糖尿病昏迷的特点是（）。

A.多见于青少年

B.无糖尿病史或轻型患者

C.神经精神症状较突出

D.有高血糖、高血钠及高血浆渗透压

E.死亡率较高

答案

参考答案：A

单项选择题

Modern industrial society grants little status to old people. In fact, such a society has a system of built-in obsolescence. There is no formal system for continuing our education throughout our life in order to keep up with rapidly changing knowledge. When our education and job skills have grown obsolete, we are treated exactly like those who have never gained an education or job skills and are not encouraged or given the opportunity to begin anew.As a society becomes more highly developed, the overall status of older people diminishes. Improved health technology creates a large pool of old people, who compete for jobs with the young. However, economic technology lowers the demand for workers and creates new jobs for which the skills of the aged are obsolete, forcing older people into retirement. At the same time, young people are being educated in the new technology and are keeping pace with rapid changes in knowledge. Finally, urbanization creates age-segregated neighborhoods. Because the old live on fixed incomes, they must often live in inferior housing. All these factors — retirement, obsolete knowledge and skills, inferior standards of living — lower the status of the aged in society.A century ago, when one could expect to live only to 50 or so, the life span more or less coincided with the occupation and family cycle. But today the average life span allows for fifteen to twenty years of life after these cycles. It appears that our life span is outpacing our usefulness in society.

Which of the following would be the best title for this passage

A．The Problem of Aging

B．Social Structures

C．Economic Technology

D．Continuing Education
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问答题

在探究“测滑轮组的机械效率”的实验中，马刚同学用如图所示的同一滑轮组进行了三次实验，实验记录如下表：

序号速度（m/s）钩码总重G（N）钩码上升高度h（m）测力计拉力F（N）测力计移动距离s（m）机械效率（%）
10.220.10.80.383.3
20.230.11.10.3 
30.420.20.80.6 
（1）将实验序号2、3所对应的机械效率填入相应表格中的空白处：

（2）根据以上实验可得到的结论是：在滑轮组的串绕绳子的方式不变时，机械效率与______有关，与______无关．
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