名词
1. 频率;发生次数
The frequency of an event is the number of times it happens during a particular period.
2. (声波或无线电波的)频率，周率
In physics, the frequency of a sound wave or a radio wave is the number of times it vibrates within a specified period of time.
1. the number of observations in a given statistical category
Synonym: absolute frequency
2. the ratio of the number of observations in a statistical category to the total number of observations
Synonym: relative frequency
3. the number of occurrences within a given time period
e.g. the frequency of modulation was 40 cycles per second
the frequency of his seizures increased as he grew older