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问题 单项选择题

铝导线和铜导线连接时，为防止电气腐蚀，应采用的防护措施是( )。

A．使用酸性熔焊剂

B．使用碱性熔焊剂

C．接头端线芯镀铜

D．接头端线芯镀锡

答案

参考答案：D

解析：[考点] 第四章通用安装工程第四节电气照明及设备安装：配管配线工程安装。 [思路] 对于铝和铝的连接，如采用熔焊法，主要防止残余熔剂或熔渣的化学腐蚀，对于铝和铜的连接，主要防止电气腐蚀。在连接前后，应采取措施避免这类腐蚀的存在(如使用铜铝过渡接头或接头端线芯镀锡等措施)，否则在长期运行中接头有发生故障的可能。 [易错] 选项C只镀铜没有任何作用，可用铜铝之间的过渡金属防止电化学反应腐蚀铜和铝。 [拓展] 导线连接的方法及基本要求。

单项选择题

Honesty comes in many forms. First there’s self honesty. Is what people see the real article or do you appear through smoke and mirrors I find that if I try to be something I’m not, I feel unsure of myself and take out a part from my PBA (personal bank account). I love how singer Judy Garland put it, "Always be a first class version of yourself, instead of a second class version of somebody else. "
Then there’s honesty in our actions. Are you honest at school, with your parents, and with your boss If you’ve ever been dishonest, I think we all have, try being honest, and notice how whole it makes you feel. Remember, you can’t do wrong and feel right. This story by Jeff is agood example of that:
In my second year of study, there were three kids in my math class who didn’t do well. I was really good at it. I would charge them three dollars for each test that I helped them pass. I’d write on a little piece of paper all the right answers, and hand them off.
At first I felt like I was making money, kind of a nice job. I wasn’t thinking about how it could hurt all of us. After a while I realized I shouldn’t do that any more, because I wasn’t really helping them! They weren’t learning anything, and it would only get harder down the road. Cheating certainly wasn’t helping me.
It takes courage to be honest when people all around you who are getting away with cheating on tests, lying to their parents, and stealing at work. But, remember, every act of honesty is a deposit into your PBA and will build strength.

What does the author expect to show by Jeff’s story

A．Honesty can be of great help.
B．A bad thing can be turned into a good one.
C．Helping others cheat can do good to nobody.
D．One should realize the wrong in his bad deeds.
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单项选择题

鉴别腹股沟斜疝、直疝，下列哪种检查最准确()

A．平卧时肿物消失为直疝，否则为斜疝

B．压迫内环口，站立咳嗽，肿物不出现为斜疝，否则为直疝

C．咳嗽肿物突出为直疝，否则为斜疝

D．指诊外环口，不增大为斜疝，增大为直疝

E．X线腹透，小肠积气为斜疝，否则为直疝．
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