英语语法分析

A nanosecond is one-billionth of a second.

1纳秒为十亿分之一秒。

TB: The implementation of nanosecond calculation presented above.

tb：上面给出的纳秒计算的实现。

Light travels basically a foot in a nanosecond. Simple rule of thumb.

光行进的速度是每纳秒一英尺，很简单的经验法则了。