问题
单项选择题
下列关于设备寿命概念的描述中，正确的是( )。
A．设备使用年限越长，设备的经济性越好
B．设备的经济寿命是由技术进步决定的
C．搞好设备的维修和保养可避免设备的有形磨损
D．设备的技术寿命主要是由设备的无形磨损决定的
答案
参考答案：D
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下列关于设备寿命概念的描述中，正确的是( )。
A．设备使用年限越长，设备的经济性越好
B．设备的经济寿命是由技术进步决定的
C．搞好设备的维修和保养可避免设备的有形磨损
D．设备的技术寿命主要是由设备的无形磨损决定的
参考答案：D
My pen friend is a kind and friendly girl. She is in England. Her is Connie. I meet Connie the Internet, and we are both twelve years . First, I a letter to her and introduce(介绍) my hobbies, my school and my daily life. A few days later, I get Connie’s . She me a lot about herself. I learn that she loves languages, sports and films. She likes China and Chinese food very much. She tells me something about England, too. Connie is good at English, French（法语）and Spanish（西班牙语）, so I ask her to me a little. Connie wants to learn some , but it’s very difficult for her. From Connie, I know about the world outside. I would like to go to England to Connie some day.
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