直流电动机的换向过程,是一个比较复杂的过程,换向不良的直接后果是()。A、电刷产生火 发布时间:2019-01-28 00:39 │ 来源:www.tikuol.com 题型:单项选择题 问题: 直流电动机的换向过程,是一个比较复杂的过程,换向不良的直接后果是()。A、电刷产生火花B、电刷发热碎裂C、电刷跳动D、电刷磨损严重
题型:单项选择题 -- You know who came to our school yesterday?-- Professor Smith? We once met at a conference.-- ______. He came and gave a wonderful speech.A.How did you know that?B.That was good news.C.Got it!D.Well Done! 查看答案