This is the basis for the well - known cesium clock, presently the standard of frequency and time.

这就是众所周知的铯原子钟的基础，它是目前的频率和时间基准。

youdao

This is the basis for the well - known cesium clock, presently the standard of frequency and time.

这就是众所周知的铯原子钟的基础，它是目前的频率和时间基准。

youdao