s electromagnet
年代电磁铁
以上为机器翻译结果，长、整句建议使用 人工翻译 。
That is because a permanent magnet's maximum strength is dictated by the material it is made from, while an electromagnet's strength depends on the current passing through it.
ECONOMIST: Maglev trains
应用推荐
模块上移
模块下移
不移动