My 12 year old had a lesson in his science course later that day that mapped magnetic fields of a little bar magnet. He showed me the results.
当天的晚些时候，我12岁的大儿子在他的自然科学课上绘制了一幅磁铁的磁场分布图。他向我展示他的成果。
2
My 12 year old had a lesson in his science course later that day that mapped magnetic fields of a little bar magnet.
当天的晚些时候，我12岁的大儿子在他的自然科学课上绘制了一幅磁铁的磁场分布图。
3
One of these was loadstone which is basically a chunk of naturally occurring iron which has somehow in the course of the earth’s long history obtained a magnetic orientation.