magnetic health ball

例句：

1. 1. The magnet is attracted to the iron bar.
   磁铁被铁棒吸引。
2. 2. Magnets are used in many industrial processes.
   磁铁在许多工业过程中被使用。
3. 3. The magnetic field around the Earth is strong.
   地球周围的磁场很强。