frequency-density是什么意思
问题描述：
frequency-density是什么意思
答
1.Their instruments detected very faint radiowaves at a frequency of 3 kilohertz.(26.5K)
他们的仪器检测到一个3千赫的微弱无线电波.
2.Fatal road accidents have decreased in frequency over recent years.
近年来致命交通事故发生率已经下降.
3.If we can know their frequency we will monitor their talking.
如果我们知道他们的频率,我们就能监听他们的谈话.