undamped medium frequency electrotherapy

例句：

1. 1. The undamped oscillator produces a pure tone.
   未受扰动的振荡器产生纯音。
2. 2. The undamped spring is capable of storing considerable energy.
   未受扰动的弹簧能储存相当的能量。
3. 3.The undamped system will respond instantaneously to any disturbances.
   未受扰动的系统会立即对任何扰动做出反应。