frequency temperature characteristic

例句：

1. 1. The frequency ofoccurrence is increasing.
   发生的频率在增加。
2. 2. Thefrequency of light waves is measured in cyclesper second.
   光波的频率是以每秒的周期数来衡量的。
3. 3. The frequency of thesignal changes with time.
   信号的频率随时间变化。