frequency number

例句：

1. 1.The frequency of earthquakes in this area is relatively high.
   这个地区的地震频率相对较高。
2. 2. The frequency of traffic accidents has decreased significantly since the implementation of safety measures.
   自从实施安全措施以来，交通事故的频率显著下降。
3. 3. The frequency of occurrence of this disease varies greatly among different populations.
   这种疾病在不同人群中的发生率差异很大。