frequency of oscillation

例句：

1. 1. The frequency ofoccurrence is increasing.
   发生的频率在增加。
2. 2. Thefrequency of light waves in the electromagneticspectrum is measured in hertz.
   电磁谱中光波的频率是以赫兹为单位测量的。
3. 3. The frequency of the signal changeswith time.
   信号的频率随时间变化。