衔铁

例句：

1. 1. The electromagnet is used toattract metal objects.
   电磁铁用于吸引金属物体。
2. 2. The coil of wire is connected tothe magnet.
   线圈与磁铁相连。
3. 3. The coreof the transformer is made of iron.
   变压器的铁芯由铁制成。