1、
Their instruments detected very faint radiowaves at a frequency of 3 kilohertz.
他们的仪器检测到一个3千赫的微弱无线电波。
《柯林斯高阶英汉双解学习词典》
2、
3、
Twisted-pair conductors are sufficient if frequencies of interest are below a few hundred kilohertz.
如果信号频率低于几百kHz,则使用双绞线就已足够.
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