单词：residual current operated protective device
单词：residual current operated protective device 相关文章
[00:05.20]Nikola Tesla developed the alternating current power system that provides electricity in the United States. [00:14.42]Many of his other discoveries led to electronic inventions for which other scientists were honored. [00:22.75]Mister Tesla
美国英语听力80篇
EXPLORATIONS -April 3, 2002: Spacesuit History By Paul Thompson VOICE ONE: This is Mary Tillotson. VOICE TWO: And this is Steve Ember with the VOA Special English program EXPLORATIONS. Today we tell a
Explorations
It was three o'clock. She was learning how to roller-skate. She had always wanted to learn. She could not afford to buy roller-skates before. Now, she was older. She had a job. She bought her first pair of roller-skates yesterday. It is never too lat
英语第3级听力-English Level 3
LONDON, June 16 (Xinhua) -- Drillings and fillings at the dentist's are always dreadful and make tooth decay treatment very unpleasant. But British scientists have developed a new approach of fixing tooth decay, which could get rid of all the drillin
英语新闻
When Feeding Birds, Think Safety and Health Feeding birds is a popular way to watch wildlife during the winter months. But many bird experts say the experience is often more pleasant for people than for birds. And it might even put wild birds at risk
2019年VOA慢速英语(二)月
Phil:So it's natural for Claire to wonder about you and her dad. This family is very protective of each other. I remember the first time Claire brought me home. Do you think Jay thought I was good enough for his little girl? No way. But, over time,
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