These small magnets can free rotation, peacetime its direction desultorily, magnetic mutualoffset, the whole object does not show magnetism.
这些小磁铁可以自由转动，平时它们的方向杂乱无章，磁性相互抵消，整个物体不显磁性。
2
The algorithm can deal with mutual inductance or non mutual inductance network and especial 'a stroke' tree set network or general offset-trees network.