问题
单项选择题
在三相异步电动机正反转控制线路中，接触器联锁触头应是对方接触器的（）。
A.主触头
B.辅助常开触头
C.辅助常闭触头
D.延时触头
答案
参考答案：C
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在三相异步电动机正反转控制线路中，接触器联锁触头应是对方接触器的（）。
A.主触头
B.辅助常开触头
C.辅助常闭触头
D.延时触头
参考答案：C
| 完形填空。 | ||||
| When someone asks me what business I am in. My face feels 1______. I envy (嫉妒) people who can say that they are writers, bookkeepers or doctors. I really do make a living by 2______. I can laugh like a king or like a school boy. It is a skill (技能) that I have learned, 3______ the skill of making shoes. Whenever and however laughter (笑声) is needed, I am asked to do 4______. I laugh like a bus driver or a shopkeeper. I laugh 5______, kindly and happily. I hardly point out that a 6______ of this kind is tiring (辛苦的). I spend most evenings in nightclubs. My job is 7______ laugh during the weaker part of the show. My loud laughter must be timed (合节拍) carefully. It must not come too soon, but neither must it be too late. I go through life quietly. I 8______ copy the laughter of others. I can laugh 9______ many different ways, but I'm not sure that I have ever heard the sound of 10______ own laughter. | ||||
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