點分發電機同電動機?因参考書既圖都係有正,負來發電?
用中文答.
唔好copy一大篇野比我.
收錄日期: 2021-04-12 18:44:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070308000051KK03432