magnetic disk

例句：

1. 1. The magnetattracts iron filings to it.
   磁铁吸引铁屑。
2. 2. The magnetic field around theEarth is strong.
   地球周围的磁场很强。
3. 3. Magnetic tape is used for recording andreproducing sound.
   磁带用于录音和重放声音。