它主要成份是两个尺寸、形状相同磁力相等的永久性磁铁。

Its main components are two sizes, shapes, the same as a permanent magnet magnetic equivalent.

youdao

它主要成份是两个尺寸、形状相同磁力相等的永久性磁铁。

Its main components are two sizes, shapes, the same as a permanent magnet magnetic equivalent.

youdao