zài / cí / tiě / zhōu / wéi / sǎ / shàng / tiě / xiè / jiù / néng / guān / chá / dào / cí / lì / xiàn / de / fēn / bù在磁铁周围撒上铁屑,就能观察到磁力线的分布。Sprinkling iron filings around a magnet makes it possible to observe the distribution of magnetic field lines.