知識頻道What is the time? How long is 1 second? Teacher Li Yongle 李永樂老師:時間是什麼? 1秒有多長? 0 What is the time? How long is 1 second? Teacher Li Yongle speaks about quartz clock and atomic clock 李永樂老師:時間是什麼? 1秒有多長? 李永乐老师 Youtube 頻道 Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Like this:Like Loading... Related