所以镁条的频率是，大概2100赫兹，你可以听到。

So the frequency for this magnesium bar is about 2,100 Hertz, and you can hear that.

youdao

所以镁条的频率是，大概2100赫兹，你可以听到。

So the frequency for this magnesium bar is about 2,100 Hertz, and you can hear that.

youdao