常用超低频信号发生器的输出只有几种固定的波形，不能更改。

The output of common ultralow frequency signal generator has only a few fixed waveforms which can not be changed.

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常用超低频信号发生器的输出只有几种固定的波形，不能更改。

The output of common ultralow frequency signal generator has only a few fixed waveforms which can not be changed.

youdao