异步电动机可以通过改变电源频率、改变()和改变磁极对数三种方法调速。 发布时间:2017-11-28 00:10 │ 来源:www.tikuol.com 题型:填空题 问题: 异步电动机可以通过改变电源频率、改变()和改变磁极对数三种方法调速。
题型:填空题 John _____Disneyland. He is still there. [ ]A. has been toB. has gone toC. went toD. goes to 查看答案