这个现象的发生频率较低。

zhège xiànxiàng de fāshēng pínlǜ jiào dī.

The frequency of this phenomenon is relatively low.

无线电台的频率很稳定。

wúxiàndiàntái de pínlǜ hěn wěndìng.

The frequency of the radio station is very stable.

我们要关注地震的频率。

wǒmen yào guānzhù dìzhèn de pínlǜ.

We need to pay attention to the frequency of earthquakes.