问题 单项选择题

TN系统的下列电气设备不带电部分不用做保护接零的是()。

A.在木质、沥青等不良导电地坪干燥房间内、380V及以下电压的电气装置金属外壳

B.配电装置的金属箱体、框架及靠近带电部分的金属围栏和金属门

C.潮湿或条件特别恶劣施工现场的电气设备必须采用保护接零

D.电机、变压器、电气、照明器具、手持电动工具的金属外壳,电气设备传动装置的金属部件,配电柜与控制柜的金属框架

答案

参考答案:A

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Growing up on a tobacco farm, Emma Avery was used to hard times. When she was seven, her family’s farmhouse burned to the ground. Her father made a temporary (临时的) shelter, where eight people had to sleep in two beds. As soon as Emma and her four brothers and two sisters were big enough, they were out in the fields.

Emma would find her comfort in school, even as a C student, thanks to one teacher. When she moved on to middle school, Emma was alarmingly far behind her classmates. She kept her head down, trying not to be noticed, struggling to catch up, and feeling like an outsider.

Then one day, when Emma was 16, a teacher named Mr. Potts changed everything. Looking his students in the eye, Mr. Potts said, "Being a C student does not mean you do not have a valuable contribution to make. Some of you have to work in the fields in the evening and do not have time to study. But if you do your best, you have a gift to give."

The teacher’s words made Emma believe she could do well, and she worked harder. In the end she won a scholarship to St. Paul’s College, graduated with a degree in elementary education in 1967, and got a job in the public-school system. Then, at George Washington University, she received a master’s in education in 1970, and afterwards in the same year she married Ron Smothers.

Over the next six years, Emma taught in public schools in Miami. In 1976, after saving $10,000, she opened her first restaurant in Los Angeles. Eventually Emma stopped teaching, and her business expanded (扩展) to six restaurants.

In gratitude (感激) for what she has been able to achieve, Emma donates a lot. She has no idea how much money she’s given away. She says, "Those I want to help are the C students who just need help, direction and confidence."

小题1:The first paragraph serves to show that Emma ______.

A.was poor and had no time to study

B.was born on a tobacco farm

C.was sad to lose her house

D.was kind enough to help support the family小题2:From the text we learn that Emma ______.

A.won a scholarship to George Washington University

B.was unsuccessful as a businesswoman

C.was thankful to Mr. Potts

D.disliked teaching, and gave up the job小题3:From the second paragraph we can infer that Emma was ______.

A.unintelligent

B.unconfident

C.hard-working

D.Considerate小题4:The text mainly wants to tell us ______.

A.confidence is the first step to success

B.memory of the past is the teacher of the future

C.something attempted, something done

D.nothing is impossible to a willing heart