【判断题】【消耗次数:1】
衰老期出现在数控机床使用的后期,其特点是故障率随着运行时间的增加而升高。该说法( )
正确
错误
参考答案:
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相关题目
【单选题】 数控机床的整个使用寿命期分为初期运行期、有效寿命期和衰老期。该说法( )
①  正确
②  错误
【单选题】 初期运行期的特点是故障发生的频率高,系统的故障率呈正指数曲线函数。该说法( )
①  正确
②  错误
【单选题】 下列关于数控机床的特点说法错误的是( )
①  加工零件的适应性强,灵活性好
②  加工精度高,产品质量稳
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⑤  生产管理水平提高
⑥  增加工人劳动强度
【单选题】 数控机床具有高效率的特点。该说法( )
①  正确
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【单选题】 数控装置是数控机床的核心。该说法( )
①  正确
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【单选题】 数控系统是数控机床的重要部分,它随着计算机技术的发展而发展。该说法( )
①  正确
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【单选题】 数控机床机械故障包括对机床运行装填的识别、预测和监控等三个方面的内容。该说法( )
①  正确
②  错误
【单选题】 无论是处于哪一个故障期,数控机床故障诊断的一般步骤都是相同的。该说法( )
①  正确
②  错误
【判断题】 利用报警号进行故障诊断是数控机床故障诊断的主要方法之一。该说法( )
①  正确
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【单选题】 阅读理解:阅读下列短文,回答文后问题,选择最佳答案Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important.In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily;but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago,a rich and powerful country cut down its trees to build warships, with which to gain itself an empire.It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒).5. Which title best fits the passage?
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②  B. The Function of Tree Wood
③  C. How do People do with Trees?
④  D. The Usage of Tree Roots
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