frequency calibrated recording paper

例句：

1. 1.The frequency of occurrence is 50%.
   发生的频率是50%。
2. 2. The frequency of light waves is measured in cycles per second.
   光波的频率是以每秒的周期数来衡量的。
3. 3. The frequency of the signal is 100 Hz.
   信号的频率是100赫兹。